TAPBP and colorectal carcinoma: APM majorly includes antigen peptide generation (PSMB9, PSMB8), transport (TAP1, TAP2), loading (TAPBP) and presentation of the HLA-I complex (B2M-related HLA-A, HLA-B and HLA-C).26 Here, we found that GBP2 expression was significantly positively correlated with HLA-I APM expression in the six CRC cohorts (figure 5F; online supplemental figure S8c).