In view of the importance of immune checkpoints in cancer treatment, the expression of 13 checkpoint genes (BTLA, TNFRSF9, ICOS, PDCD1, TIGIT, CTLA4, LAG3, CD274, TNFRSF4, HAVCR2, SIRPA, CD47 and VTCN1) were compared. This evidence concerns the gene PDCD1 and cancer.