Furthermore, in terms of cancer types, relatively higher expressions of PD-1 and CTLA4 in SARC and SKCM compared to the others, elevated expressions of PD-L2 in GBM, SARC and SKCM, and similar levels of PD-L1 expressions across cancer types were observed (Fig. 4d). This evidence concerns the gene PDCD1LG2 and cancer.