CD8A and colorectal cancer: A recent study shows the increased percentage of Tim-3 and PD-1 on circulating CD4+ and CD8+ T cells is associated with dysfunction of cell-mediated immunity after colorectal cancer operation, while the relationship between the expression of Tim-3+PD-1+CD8+ T cells with clinicopathological parameters, the expression and function of Tim-3 and PD-1 in TILs have not been determined in their study [40].