TAP2
Overview
TAP2 (Transporter Associated with Antigen Processing 2) encodes the beta subunit of the TAP transporter complex, which is essential for MHC class I antigen presentation. TAP2, together with TAP1, forms a heterodimeric ABC transporter that shuttles peptides from the cytoplasm into the endoplasmic reticulum for loading onto MHC class I molecules. Loss of TAP2 function disrupts antigen presentation and enables tumor immune evasion.
Alterations observed in the corpus
- Component of the MHC class I antigen-processing machinery (APM); enriched for somatic mutations in TIL-rich colorectal tumors, consistent with immune-escape selection pressure in tumors with high neoantigen load, in a cohort of 619 CRC cases PMID:27149842.
Cancer types (linked)
- COAD / Colorectal cancer: Somatic mutations in APM components including TAP2 are enriched in TIL-rich tumors, suggesting adaptive immune-escape selection PMID:27149842.
Co-occurrence and mutual exclusivity
Therapeutic relevance
- Mutations in APM genes including TAP2 represent a candidate adaptive resistance mechanism to immune-checkpoint blockade; HLA/APM-mutant tumors may be less responsive to anti-PD-1/PD-L1 therapy (hypothesis, not directly tested in citing study) PMID:27149842.
Open questions
- Whether TAP2 mutations confer primary or acquired resistance to checkpoint inhibitors in colorectal cancer was not tested in the citing study and is explicitly flagged as an open question PMID:27149842.
Sources
This page was processed by entity-page-writer on 2026-05-15.