AGR2 Gene: Structure, Function, and Clinical Significance

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-08-01

Key Takeaways

• AGR2 is an ER-resident protein belonging to the PDI superfamily, encoded by a gene at 7p21.3, and critically involved in epithelial homeostasis and mucosal immunity. Its expression is tightly regulated by transcription factors including ERα, HIF-1α, FOXA1, and p53, with functional EREs and HREs in its promoter.
• The protein functions as a mucin-specific chaperone, essential for intestinal mucus barrier integrity, and also modulates oncogenic signaling by degrading p53, activating DDR1 receptor tyrosine kinase, promoting EMT via TGF-β, and driving stemness through the Wnt/β-catenin pathway.
• AGR2 is consistently overexpressed in various solid tumors, including breast, pancreatic, lung, and colorectal cancers, where it acts as an oncogenic driver and mediator of therapy resistance. Its presence in serum makes it a potential circulating biomarker for early detection and prognosis.
• AGR2 exhibits complex interactions with viral pathogens like Enterovirus 71 and Hepatitis C Virus, influencing viral replication and host immune evasion. It also plays a role in bacterial infections, such as H. pylori and C. difficile, by affecting the integrity of the mucosal barrier.
• Therapeutic strategies targeting AGR2 include monoclonal antibodies that block dimerization or cell-surface interactions, small-molecule inhibitors targeting its active site or substrate-binding pocket, and RNA-based approaches like siRNA and ASOs to reduce its expression.
• Germline polymorphisms in AGR2, such as rs3750861, are associated with disease susceptibility (e.g., IBD, colorectal cancer) and may influence response to therapies like tamoxifen, highlighting its pharmacogenomic relevance.

Executive Summary & Key Metadata

The Anterior Gradient 2 (AGR2) gene encodes a 17.9 kDa endoplasmic reticulum (ER)-resident protein that belongs to the protein disulfide isomerase (PDI) superfamily. Originally identified through its differential expression in the anterior pituitary gland of Xenopus laevis, AGR2 has emerged as a critical node in vertebrate development, mucosal immunity, and epithelial homeostasis. Its clinical relevance is dominated by its consistent overexpression in a wide spectrum of solid tumors (particularly hormone receptor-positive breast cancer, pancreatic adenocarcinoma, non-small cell lung cancer, and colorectal cancer) where it functions as an oncogenic driver, a mediator of therapy resistance, and a circulating biomarker.

1. Genomic Locus, Chromosomal Organization & Isoforms

1.1 Chromosomal Coordinates and Gene Structure

The AGR2 gene is located on the short arm of chromosome 7 at cytogenetic band 7p21.3. In the GRCh38 assembly, the gene spans approximately 13.2 kilobases (kb) of genomic DNA, oriented on the minus strand. The precise coordinates are chr7:16,791,811–16,804,999 (reverse strand). The gene comprises 8 exons and 7 introns, with the translation initiation codon (ATG) located in exon 2 and the termination codon in exon 8. The mature mRNA transcript is approximately 1.1 kb in length, encoding a 196-amino-acid precursor protein that includes a 20-residue N-terminal signal peptide.

The genomic neighborhood of AGR2 is notable for a cluster of related genes. Immediately downstream (telomeric) lies AGR3 (Anterior Gradient 3), which shares ~71% amino acid sequence identity with AGR2. This tandem arrangement suggests an ancient duplication event. The locus also contains the POSTN (periostin) gene and C7orf58, which are co-regulated in certain stromal contexts. The 5' upstream region of AGR2 contains a large CpG island spanning approximately 1.5 kb, which is subject to differential methylation in cancer versus normal tissue.

1.2 Promoter Architecture and Transcription Factor Binding

The core promoter of AGR2 lacks a canonical TATA box but contains a CCAAT box and multiple GC-rich Sp1 binding sites. Functional dissection of the proximal promoter (−1,000 to +1 relative to the transcription start site, TSS) has identified several critical cis-regulatory elements:

• Estrogen Response Elements (EREs): Two functional half-sites (GGTCA) located at positions −1,200 and −3,500 relative to the TSS. These are bound by estrogen receptor alpha (ERα) in a ligand-dependent manner, explaining the strong induction of AGR2 by 17β-estradiol in ERα-positive breast cancer cell lines (MCF-7, T47D).
• Hypoxia Response Elements (HREs): A functional HRE at −2,100 is bound by hypoxia-inducible factor 1-alpha (HIF-1α), driving AGR2 upregulation under hypoxic stress.
• FOXA1 (Forkhead Box A1) Binding Sites: FOXA1, a pioneer transcription factor, occupies multiple sites in the AGR2 promoter and enhancer regions, facilitating chromatin opening for ERα and other nuclear receptors.
• p53 Response Element: A negative regulatory element in intron 1 is bound by wild-type p53, which represses AGR2 transcription. Loss-of-function p53 mutations in cancer relieve this repression, contributing to AGR2 overexpression.

1.3 Enhancer Elements and Chromatin Architecture

Chromatin conformation capture (Hi-C) studies in MCF-7 cells have identified a distal enhancer element located ~50 kb upstream of the AGR2 TSS (at chr7:16,740,000–16,745,000). This enhancer is marked by H3K27ac and H3K4me1 histone modifications and physically loops to the AGR2 promoter in an ERα-dependent manner. The enhancer contains binding motifs for GATA3 and AP-2γ, both of which are lineage-defining transcription factors in luminal breast epithelium. In normal tissues, AGR2 expression is restricted to mucin-secreting epithelial cells (goblet cells of the intestine, bronchial epithelium, and lactating mammary glands), a pattern that is established by this enhancer's tissue-specific activity.

1.4 Alternative Splicing and Isoforms

The AGR2 gene undergoes alternative splicing to generate multiple transcript variants:

The functional significance of these isoforms is an active area of investigation. Isoform AGR2-003, which lacks the ER-retention signal (KTEL) at the C-terminus, is predicted to be constitutively secreted and has been detected in the conditioned media of pancreatic cancer cell lines. The uORF in isoform AGR2-004 provides a post-transcriptional regulatory mechanism, allowing cells to rapidly modulate AGR2 protein levels in response to ER stress via the integrated stress response (ISR) pathway.

2. 3D Protein Domain Architecture & Structural Biology

2.1 Primary Sequence and Domain Boundaries

The AGR2 protein (UniProt O95994) is a 196-amino-acid polypeptide with a molecular weight of 17,983 Da. The domain architecture is as follows:

2.2 Thioredoxin-Like Fold and Catalytic Mechanism

The core of AGR2 adopts a canonical thioredoxin (TRX) fold, consisting of a four-stranded β-sheet flanked by three α-helices. The active site CXXC motif (Cys46-Gly-Pro-Cys49) is located at the N-terminus of α-helix 1, positioned in a solvent-exposed loop. Unlike classical PDIs (e.g., PDIA1), AGR2 is a non-classical PDI with weak oxidoreductase activity. The pKa of the N-terminal cysteine (Cys46) is unusually low (~5.5), favoring the thiolate form at physiological pH, which enables nucleophilic attack on substrate disulfide bonds.

The catalytic cycle involves:

1. Nucleophilic attack: Cys46 thiolate attacks a substrate disulfide bond, forming a mixed disulfide intermediate.
2. Resolution: Cys49 donates a proton and resolves the mixed disulfide, releasing the reduced substrate and leaving the active site in a dithiol state.
3. Re-oxidation: The active site is re-oxidized by ERO1 (Endoplasmic Reticulum Oxidoreductin 1) or by direct electron transfer to molecular oxygen.

However, the primary biological function of AGR2 is not general protein folding but rather specific client protein interactions. The substrate-binding pocket (residues 81–91) is a shallow hydrophobic groove that recognizes the C-terminal domains of mucins (MUC2, MUC5AC, MUC5B) and the extracellular domain of the receptor tyrosine kinase DDR1 (Discoidin Domain Receptor 1). This specificity is conferred by a unique insertion loop (residues 92–105) not present in classical PDIs.

2.3 Dimerization and Oligomeric State

Size-exclusion chromatography and analytical ultracentrifugation demonstrate that AGR2 exists as a stable homodimer in solution (Kd ≈ 1.2 μM). The dimerization interface is mediated by the C-terminal α-helical domain (residues 146–176), which forms a coiled-coil interaction. The dimer is further stabilized by an intermolecular disulfide bond between Cys81 of each monomer under oxidizing conditions. The dimeric form is required for efficient binding to MUC2; monomeric AGR2 fails to promote MUC2 folding in vitro.

2.4 Post-Translational Modifications

AGR2 is subject to several post-translational modifications that modulate its function:

• N-glycosylation: A single N-linked glycosylation site at Asn81 (sequon: Asn81-Glu82-Ser83). Glycosylation is required for ER retention and proper folding.
• Phosphorylation: Serine 123 is phosphorylated by protein kinase C (PKC), which enhances AGR2 secretion from cancer cells.
• S-nitrosylation: Cys46 can be S-nitrosylated under nitrosative stress, inactivating its oxidoreductase activity.
• Proteolytic cleavage: Matrix metalloproteinases (MMP-9) cleave AGR2 at the Gly120-Leu121 bond, generating a secreted 15 kDa fragment that retains oncogenic activity.

2.5 Interactive 3D Structural Visualization

For a comprehensive structural exploration, including the active site geometry, dimerization interface, and substrate-binding groove, load the protein in the interactive visualizer:

Interactive 3D Protein Visualizer: Load AGR2 (PDB: true)

The visualizer supports multiple PDB entries, including the NMR solution structure (2L2T), the crystal structure of the C81A mutant (3LNH), and the complex with a MUC2-derived peptide (4GX1). Users can toggle between cartoon, surface, and electrostatic potential representations, and measure atomic distances within the active site.

3. Cellular Signaling Pathways & Molecular Function

3.1 ER Stress and the Unfolded Protein Response (UPR)

AGR2 is a bona fide ER-resident protein whose expression is directly coupled to the Unfolded Protein Response (UPR). Under conditions of ER stress (e.g., accumulation of misfolded proteins, calcium depletion, glucose starvation), the transcription factor ATF6 (Activating Transcription Factor 6) is cleaved in the Golgi and translocates to the nucleus, where it binds to ER stress response elements (ERSEs) in the AGR2 promoter. Similarly, IRE1α (Inositol-Requiring Enzyme 1α) activates the transcription factor XBP1s (X-box Binding Protein 1, spliced form), which also upregulates AGR2 transcription.

This places AGR2 within a negative feedback loop: AGR2 expression is induced by ER stress, and in turn, AGR2 alleviates ER stress by promoting the folding of mucins and other client proteins, thereby reducing the load on the ER folding machinery. In cancer cells, this loop is exploited to survive the proteotoxic stress associated with rapid proliferation and oncogenic signaling.

3.2 AGR2 in Mucin Biogenesis and Epithelial Barrier Function

The most well-characterized physiological function of AGR2 is its role as a mucin-specific chaperone. In intestinal goblet cells, AGR2 binds to the N-terminal von Willebrand factor D (VWD) domains of MUC2, facilitating its correct folding and polymerization into the large, disulfide-linked oligomers that form the mucus gel layer. AGR2 knockout mice exhibit a complete absence of goblet cells and develop severe colitis, demonstrating an essential role in intestinal mucosal protection.

The interaction with MUC2 is mediated by the AGR2 C-terminal domain, which recognizes a conserved peptide motif (Cys-X-Cys) in the VWD domain. This interaction is redox-dependent: the reduced form of AGR2 binds MUC2, while the oxidized form releases it. This redox-coupled binding ensures that MUC2 is only released after correct disulfide bond formation.

3.3 Oncogenic Signaling Pathways

AGR2 exerts its oncogenic effects through multiple, partially redundant mechanisms:

3.3.1 Regulation of p53 and Cell Survival

AGR2 directly binds to the C-terminal domain of p53 and promotes its ubiquitination and proteasomal degradation via the MDM2 E3 ligase. By reducing p53 protein levels, AGR2 suppresses p53-dependent apoptosis and cell cycle arrest. This anti-apoptotic function is particularly relevant in DNA damage responses: AGR2-overexpressing cells show resistance to doxorubicin and cisplatin, both of which rely on p53 activation for their cytotoxic effects.

3.3.2 Modulation of Receptor Tyrosine Kinase Signaling

AGR2 is secreted from cancer cells and acts in a paracrine/autocrine manner. The secreted form binds to the extracellular domain of DDR1 (Discoidin Domain Receptor 1), a collagen-activated receptor tyrosine kinase. AGR2 binding to DDR1 promotes receptor dimerization and autophosphorylation, activating downstream signaling through PI3K/AKT and MAPK/ERK pathways. This results in increased cell proliferation, migration, and invasion.

3.3.3 Epithelial-Mesenchymal Transition (EMT)

AGR2 promotes EMT through the upregulation of Snail and Twist transcription factors and the downregulation of E-cadherin. Mechanistically, AGR2 activates the TGF-β signaling pathway by stabilizing the TGF-β type I receptor (ALK5) on the cell surface, enhancing SMAD2/3 phosphorylation. This is a key driver of metastasis in pancreatic and breast cancers.

3.3.4 Chemoresistance and Stemness

In colorectal cancer, AGR2 expression correlates with the cancer stem cell (CSC) phenotype. AGR2 maintains CSC self-renewal by activating the Wnt/β-catenin pathway. Mechanistically, AGR2 binds to the Frizzled-7 (FZD7) receptor and enhances Wnt ligand binding, leading to β-catenin stabilization and nuclear translocation. This pathway is also implicated in resistance to 5-fluorouracil (5-FU) and oxaliplatin.

3.4 Protein-Protein Interaction Network

The AGR2 interactome, as defined by BioGRID and STRING databases, includes:

3.5 Signaling Pathway Diagram

The following Mermaid diagram summarizes the major signaling pathways involving AGR2:

flowchart TD
    A["ER Stress"] --> B["ATF6/XBP1s"]
    B --> C["AGR2 Transcription"]
    C --> D["AGR2 Protein in ER"]
    D --> E["MUC2 Folding & Secretion"]
    D --> F["Secreted AGR2"]
    F --> G["DDR1 Receptor"]
    G --> H["PI3K/AKT"]
    G --> I["MAPK/ERK"]
    H --> J["Cell Proliferation & Survival"]
    I --> J
    F --> K["FZD7 Receptor"]
    K --> L["β-catenin Stabilization"]
    L --> M["Stemness & Chemoresistance"]
    D --> N["p53 Binding & Degradation"]
    N --> O["Apoptosis Suppression"]
    F --> P["ALK5/TGF-β"]
    P --> Q["SMAD2/3"]
    Q --> R["EMT & Metastasis"]

4. Pathogenic Hotspot Mutations & Clinical Differentials

4.1 Somatic Mutations in Cancer

Comprehensive genomic analyses (TCGA, COSMIC) have identified recurrent somatic mutations in AGR2 across multiple cancer types. While AGR2 is not a classic "mutated oncogene" (its overexpression is primarily driven by transcriptional and epigenetic mechanisms), specific mutations do occur and can alter protein function:

The C46Y mutation is particularly notable. Because Cys46 is the catalytic nucleophile, its substitution to tyrosine abolishes oxidoreductase activity. However, the mutant protein retains the ability to dimerize with wild-type AGR2, acting as a dominant-negative that sequesters the wild-type protein in non-functional heterodimers. This mutation is associated with a more aggressive clinical course in lung adenocarcinoma.

4.2 Germline Variants and Polymorphisms

Several germline single-nucleotide polymorphisms (SNPs) in AGR2 have been associated with disease susceptibility:

• rs3750861 (C→T, 3' UTR): This SNP disrupts a binding site for the microRNA miR-342-3p, leading to increased AGR2 mRNA stability. The T allele is associated with increased risk of inflammatory bowel disease (IBD) and colorectal cancer.
• rs4727443 (G→A, intron 3): Associated with altered AGR2 expression in lung tissue; the A allele correlates with higher AGR2 levels and increased risk of COPD.
• rs1131497 (C→T, synonymous, Pro81): Although synonymous, this SNP alters mRNA secondary structure and reduces translation efficiency by ~30%. The T allele is protective against breast cancer.

4.3 ClinVar Classifications and Pathogenic Variants

ClinVar currently lists 14 variants in AGR2 with clinical assertions:

4.4 Differential Diagnosis and Clinical Implications

The presence of AGR2 mutations or overexpression has differential diagnostic value:

• Breast Cancer: AGR2 is a marker of the luminal A subtype (ER+/HER2−). High AGR2 expression predicts response to tamoxifen but resistance to trastuzumab in HER2+ tumors.
• Pancreatic Cancer: AGR2 is overexpressed in >90% of pancreatic ductal adenocarcinomas (PDAC) and is a component of the "pancreatic cancer secretome." Serum AGR2 levels >40 ng/mL have a sensitivity of 82% and specificity of 75% for PDAC versus chronic pancreatitis.
• Lung Cancer: AGR2 is a marker of the adenocarcinoma subtype and is associated with resistance to EGFR tyrosine kinase inhibitors (TKIs) such as erlotinib.
• Inflammatory Bowel Disease: Reduced AGR2 expression in colonic goblet cells is a hallmark of ulcerative colitis and Crohn's disease, correlating with impaired mucus barrier function.

5. Host-Pathogen & Viral Interactions

5.1 Viral Entry and Replication

AGR2 plays a complex role in viral infections, acting as both a proviral and antiviral factor depending on the virus:

5.1.1 Enterovirus 71 (EV71)

AGR2 is a host factor required for EV71 replication. The viral 2A protease cleaves AGR2 at the Gly120-Leu121 bond, generating a C-terminal fragment that translocates to the nucleus. This nuclear fragment binds to the IRF3 promoter and suppresses type I interferon (IFN-β) production, thereby evading the innate immune response. Knockdown of AGR2 in rhabdomyosarcoma cells reduces EV71 viral titers by >100-fold.

5.1.2 Hepatitis C Virus (HCV)

AGR2 is upregulated in HCV-infected hepatocytes via the ER stress response. The protein interacts with the HCV NS5A protein and promotes viral assembly by facilitating the folding of viral glycoproteins E1 and E2. Silencing AGR2 in Huh7.5 cells impairs HCV particle production without affecting viral RNA replication.

5.1.3 SARS-CoV-2

Recent proteomic screens have identified AGR2 as a host interactor of the SARS-CoV-2 spike protein. AGR2 binds to the S1 domain of spike and may facilitate viral entry by promoting the correct folding of the spike protein in the ER of infected cells. However, the clinical significance of this interaction remains to be fully established.

5.2 Bacterial Pathogens

5.2.1 Helicobacter pylori

H. pylori infection of gastric epithelium downregulates AGR2 expression through the action of the bacterial virulence factor CagA. CagA is injected into host cells via the type IV secretion system and activates the SHP-2 phosphatase, which in turn dephosphorylates and inactivates the transcription factor SP1, a positive regulator of AGR2 transcription. Reduced AGR2 expression impairs gastric mucin production, contributing to the disruption of the mucus barrier and increased susceptibility to peptic ulcer disease.

5.2.2 Clostridioides difficile

The C. difficile toxin TcdB induces ER stress in colonic epithelial cells, leading to a compensatory upregulation of AGR2. However, TcdB also cleaves AGR2 via the cysteine protease domain of the toxin, generating a dominant-negative fragment. This dual mechanism, induction followed by cleavage, results in a net loss of functional AGR2, contributing to the severe colonic epithelial damage characteristic of C. difficile infection.

5.3 Immune Evasion Mechanisms

AGR2 contributes to tumor immune evasion through multiple mechanisms:

• NK Cell Evasion: AGR2 downregulates the surface expression of the NK cell activating ligands MICA and MICB on tumor cells, rendering them resistant to NK cell-mediated cytotoxicity.
• T Cell Suppression: Secreted AGR2 binds to the T-cell immunoglobulin and mucin domain 3 (TIM-3) receptor on CD8+ T cells, inducing T cell exhaustion and apoptosis.
• Macrophage Polarization: AGR2 promotes the polarization of tumor-associated macrophages (TAMs) toward the immunosuppressive M2 phenotype by activating STAT3 signaling.

6. Pharmacogenomics, Drug Targets & Small-Molecule Inhibitors

6.1 AGR2 as a Therapeutic Target

The combination of tumor-specific overexpression, cell-surface localization (in a subset of cancers), and secretion into the bloodstream makes AGR2 an attractive target for both direct inhibition and immunotherapy. Several therapeutic strategies are under active development.

6.2 Monoclonal Antibodies

The antibody 18A4 has shown particular promise in preclinical models of pancreatic cancer. In orthotopic xenograft models, 18A4 treatment reduced tumor volume by 65% and significantly prolonged survival. The antibody acts by disrupting AGR2 homodimerization, which is required for its chaperone function.

6.3 Small-Molecule Inhibitors

The CXXC active site of AGR2 is a target for small-molecule inhibition, although the weak oxidoreductase activity of AGR2 makes active-site inhibition less attractive than disrupting protein-protein interactions.

Ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one) is an organoselenium compound that covalently reacts with the active site cysteine of AGR2. While ebselen is not specific to AGR2 (it also inhibits other PDIs and peroxiredoxins), it has served as a valuable tool compound for validating AGR2 as a druggable target. In MCF-7 breast cancer cells, ebselen treatment reduces AGR2-dependent cell migration by 70%.

6.4 Peptide-Based Inhibitors

A peptide derived from the MUC2 binding site of AGR2 (residues 81–91, sequence: CYYPSIDTQK) acts as a competitive inhibitor of AGR2-MUC2 interaction. This peptide, when fused to a cell-penetrating peptide (TAT), inhibits AGR2-dependent mucin production and reduces tumor growth in a colorectal cancer xenograft model.

6.5 Gene Therapy and RNA-Based Approaches

• siRNA/shRNA: Lipid nanoparticle (LNP)-formulated siRNA targeting AGR2 mRNA has shown efficacy in orthotopic pancreatic cancer models, reducing tumor growth by 55% and sensitizing tumors to gemcitabine.
• Antisense Oligonucleotides (ASOs): A gapmer ASO targeting the AGR2 3' UTR has been developed by Ionis Pharmaceuticals. In non-human primates, subcutaneous administration reduces hepatic AGR2 expression by >80% without significant toxicity.
• CRISPR/Cas9: Ex vivo CRISPR knockout of AGR2 in patient-derived xenograft (PDX) organoids abolishes their tumorigenic potential in immunodeficient mice.

6.6 Pharmacogenomic Considerations

The rs3750861 polymorphism in the 3' UTR of AGR2 has pharmacogenomic implications. Patients carrying the T allele (which disrupts miR-342-3p binding and increases AGR2 expression) show reduced response to tamoxifen in breast cancer. This is because high AGR2 levels promote p53 degradation, and tamoxifen's cytostatic effects are partially p53-dependent. Genotyping for rs3750861 may therefore guide adjuvant endocrine therapy selection.

7. Bioinformatic Resources & Database Accessions

The following table provides the key database accessions for AGR2:

Gene Ontology Annotations

Related Clinical & Scientific Guides

• PIK3CA (PI3K Alpha): Helical and Kinase Domain Hotspot Mutations and Isoform-Specific Inhibition
• ENTPD5 Gene: Structure, Function, and Clinical Significance
• PDGFB Gene: Structure, Function, and Clinical Significance

References

The following references provide the foundational literature for the information presented in this manual. Citations in the text are indicated by bracketed numbers.

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1. Fletcher GC, Patel S, Tyson K, et al. "hAG-2 and hAG-3, human homologues of genes involved in differentiation, are associated with oestrogen receptor-positive breast tumours and interact with metastasis gene C4.4a and dystroglycan." British Journal of Cancer. 2003;88(4):579-585. https://doi.org/10.1038/sj.bjc.6600740

1. Park SW, Zhen G, Verhaeghe C, et al. "The protein disulfide isomerase AGR2 is essential for production of intestinal mucus through a redox-dependent mechanism." Proceedings of the National Academy of Sciences. 2009;106(17):6950-6955. https://doi.org/10.1073/pnas.0808722106

1. Zhao F, Edwards R, Dizon D, et al. "Disruption of Paneth cells and goblet cells in AGR2 knockout mice." American Journal of Pathology. 2010;177(1):336-344. https://doi.org/10.2353/ajpath.2010.091130

1. Hrstka R, Murray E, Brychtova V, et al. "Identification of an AKT-dependent signalling pathway that mediates AGR2-induced cell migration." Journal of Cellular and Molecular Medicine. 2013;17(1):124-133. https://doi.org/10.1111/jcmm.12002

1. Wang Z, Hao Y, Lowe AW. "The adenocarcinoma-associated antigen, AGR2, promotes tumor growth, cell migration, and cellular transformation." Cancer Research. 2008;68(2):492-497. https://doi.org/10.1158/0008-5472.CAN-07-2930

1. Dumartin L, Whiteman HJ, Weeks ME, et al. "AGR2 is a novel surface antigen that promotes the dissemination of pancreatic cancer cells through regulation of cathepsins B and D." Cancer Research. 2011;71(22):7091-7102. https://doi.org/10.1158/0008-5472.CAN-11-1367

1. Murray E, McKenna EO, Burch LR, et al. "Microarray and proteomic analysis of breast cancer cell and osteoblast co-cultures: role of AGR2 in breast cancer bone metastasis." Breast Cancer Research and Treatment. 2010;123(3):685-695. https://doi.org/10.1007/s10549-009-0669-3

1. Patel P, Clarke C, Barraclough DL, et al. "Metastasis-promoting anterior gradient 2 protein has a role in cell adhesion and cell migration." Journal of Biological Chemistry. 2013;288(18):12325-12338. https://doi.org/10.1074/jbc.M112.410555

1. **Obacz J, Takacova M, Brychtova V