found that CD39+ γδT cells, as immunosuppressive T cells, significantly increased in the CRC tissues and highly expressed immunosuppression-related molecules, including CD25, CD161, FOXP3, programmed cell death protein 1 PD-1, CTLA-4, PD-L1, whereas they expressed markedly lower levels of immunostimulatory factors [21]. This evidence concerns the gene PDCD1 and colorectal carcinoma.