PDCD1 and colon adenocarcinoma: Our findings are consistent with a previous study that Tim-3+PD-1+CD8+ T cells are more dysfunctional in TILs and Tim-3−PD-1−CD8+ T cells are major producers of IFN-γ in the TILs of MC38 and CT26 tumor models( colon adenocarcinomas) in mice [30].