# B2M

Source: https://onco.cc/targets/b2m/  
OnCo record `b2m` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

B2M (Beta-2-microglobulin) is a gene whose normal job is to hold cell growth in check. The public catalogues list it as a drug target, an oncogene driver, a tumour suppressor and a biomarker, and clinical evidence ties its variants to diagnosis, prognosis or drug response. Tied to Non-Hodgkin lymphoma, Colorectal cancer, Lung cancer and 5 more.

## Summary

Component of the class I major histocompatibility complex (MHC). Involved in the presentation of peptide antigens to the immune system. Exogenously applied M.tuberculosis EsxA or EsxA-EsxB (or EsxA expressed in host) binds B2M and decreases its export to the cell surface (total protein levels do not change), probably leading to defects in class I antigen presentation.

CIViC holds 7 clinical evidence items and 0 assertions across 4 variants, naming Pembrolizumab, Nivolumab, Anti-PD-L1 Monoclonal Antibody and Immune Checkpoint Inhibitor and others. Open Targets scores its association with cancer at 0.69 (direct and indirect evidence; datatypes literature 0.98, affected pathway 0.61, genetic association 0.00, somatic mutation 0.88). IntOGen calls it a driver in 10 cohorts (4 activating, 6 loss-of-function), covering Cervical Squamous Cell Carcinoma, Diffuse Large B-Cell Lymphoma, NOS, Head and Neck Squamous Cell Carcinoma, Melanoma, Malignant Lymphoma, Non-Hodgkin Lymphoma and others.

## Fields

- Kind: Target
- Last checked: 2026-09-23
- Also known as: beta-2-microglobulin; Beta-2-microglobulin
- Tags: cancer-genes-wave
- Symbol: B2M
- Class: tumor-suppressor
- Biology: Component of the class I major histocompatibility complex (MHC). Involved in the presentation of peptide antigens to the immune system. Exogenously applied M.tuberculosis EsxA or EsxA-EsxB (or EsxA expressed in host) binds B2M and decreases its export to the cell surface (total protein levels do not change), probably leading to defects in class I antigen presentation. Location: Secreted; Cell surface (UniProt). Locus 15q21.1 (HGNC).
- Where found: Non-Hodgkin lymphoma: Open Targets association 0.72 with non-Hodgkin lymphoma (MONDO_0018908); IntOGen driver in 2 cohorts (MLYM, NHL); Colorectal cancer: Open Targets association 0.56 with colorectal cancer (MONDO_0005575); CIViC evidence names this disease; Lung cancer: CIViC evidence names this disease; Head and neck squamous cell carcinoma: IntOGen driver in 2 cohorts (HNSC); Cervical cancer: IntOGen driver in 1 cohort (CESC); Diffuse large B-cell lymphoma: Open Targets association 0.67 with diffuse large B-cell lymphoma (MONDO_0018905); CIViC evidence names this disease

## Notes

- Written by scripts/fetch-cancer-genes.ts from CIViC, Open Targets, IntOGen, HGNC and UniProt; the function text is UniProt's, condensed and in UK spelling. Roles: CIViC lists 5 therapies; IntOGen calls it an activating (Act) driver in 4 cohorts; IntOGen calls it a loss-of-function (LoF) driver in 6 cohorts; CIViC holds 7 clinical evidence items on its variants. Evidence tier "clinical-evidence" is the strongest of those signals.
- Prevalence not recorded: none of the sources gives a positivity rate.

## Sources

- HGNC HGNC:914: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:914
- UniProt P61769: https://www.uniprot.org/uniprotkb/P61769/entry
- NCBI Gene 567: https://www.ncbi.nlm.nih.gov/gene/567
- Ensembl ENSG00000166710: https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000166710

## Connected records

- collections: [CIViC](https://onco.cc/collections/civic/), [IntOGen](https://onco.cc/collections/intogen/), [Open Targets Platform](https://onco.cc/collections/open-targets/)
- cancers: [Cervical cancer](https://onco.cc/cancers/cervical/), [Colorectal cancer](https://onco.cc/cancers/colorectal/), [Diffuse large B-cell lymphoma](https://onco.cc/cancers/dlbcl/), [Head and neck squamous cell carcinoma](https://onco.cc/cancers/head-and-neck/), [Lung cancer (all types)](https://onco.cc/cancers/lung-cancer/), [Mantle cell lymphoma](https://onco.cc/cancers/mantle-cell-lymphoma/), [Melanoma](https://onco.cc/cancers/melanoma/), [Non-Hodgkin lymphoma (all types)](https://onco.cc/cancers/non-hodgkin-lymphoma/)
- pathways: [Antigen presentation & immune editing](https://onco.cc/pathways/antigen-presentation-immunoediting/)

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JSON: https://onco.cc/api/v1/entities/b2m.json