{"entity":{"id":"epitope","kind":"term","name":"Epitope","aka":["epitopes","binding site","binding sites","binding domain","binding domains"],"tldr":"The exact small patch on an antigen that an antibody or T cell actually grips, like the specific spot on a door handle a hand grabs. Two antibodies can bind the same protein at different epitopes.","summary":"An epitope is typically a cluster of five to fifteen amino acids on the surface of a protein. Trastuzumab and pertuzumab both bind HER2 but at different epitopes, which is why they can be given together, and zanidatamab is a single antibody built to grab both spots at once. For T cells, the epitope is a short peptide fragment held in an HLA molecule on the cell surface; a mutation that changes or removes the epitope lets a tumour cell slip past an antibody or T cell without changing anything else.","asOf":"2026-09-09","wikipedia":"https://en.wikipedia.org/wiki/Epitope","links":[{"label":"Wikipedia","url":"https://en.wikipedia.org/wiki/Epitope"}],"tags":[],"related":["antigen","antibody","neoantigen","t-cell"],"cancers":[],"sections":[],"technologies":[],"targets":["her2"],"drugs":["trastuzumab","zanidatamab"],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"category":"Biology basics"},"route":"/terms/epitope/","neighbours":{"term":[{"id":"antibody","kind":"term","name":"Antibody","route":"/terms/antibody/"},{"id":"antigen","kind":"term","name":"Antigen","route":"/terms/antigen/"},{"id":"neoantigen","kind":"term","name":"Neoantigen","route":"/terms/neoantigen/"},{"id":"t-cell","kind":"term","name":"T cell","route":"/terms/t-cell/"}],"target":[{"id":"her2","kind":"target","name":"HER2","route":"/targets/her2/"}],"drug":[{"id":"trastuzumab","kind":"drug","name":"Trastuzumab","route":"/drugs/trastuzumab/"},{"id":"zanidatamab","kind":"drug","name":"Zanidatamab","route":"/drugs/zanidatamab/"}]}}