MTAP and colorectal carcinoma: 9p21 loss and/or MTAP-loss has previously been associated with poor response to cancer immunotherapy and hypothesized to be related to immune evasion via cell cycle, metabolic, and type I interferon response pathways.43 In the Genomics-only cohort, we found that MTAP-loss CRC, IHCC, and PDAC were significantly less likely to harbor MSI-H.