CD8A and colorectal carcinoma: For instance, MSI high CRC tumors had increased enrichment of cytotoxic CD8 + T-cells, natural killer (NK) cells, Th1 helper T-cells, and a greater degree of Th17 T-cell activation in comparison to MSS counterparts.[52] Moreover, MSI high tumors have an underenrichment of T-regulatory cells.[52] In contrast, immunosuppressive TME predominates in MSS GI cancers.