CD8A and colon adenocarcinoma: Furthermore, the protein expression of MLH1, MSH2 (MMR markers), PD-L1 (marker for T-cells, B-cells and tumor cells), CD8 (CTL marker), FOXP3 (Treg marker) and CD66b (TAN marker) was evaluated by IHC in FFPE tissue derived from the same patients in the cohort (47 pMMR/MSS, 13 dMMR/MSI-L and 12 dMMR/MSI-H colon adenocarcinomas).