PDCD1LG2 and central nervous system cancer: In gliomas, CASP4 expression was positively correlated with the expression of major immune checkpoint inhibitor molecules, such as CD96 (r = 0.55, P < 0.0001), CD274 (r = 0.53, P < 0.0001), CSF1R (r = 0.34, P < 0.0001), HAVCR2 (r = 0.71, P < 0.0001), IL10 (r = 0.69, P < 0.0001), IL10RB (r = 0.78, P < 0.0001), PDCD1 (r = 0.43, P < 0.0001), and PDCD1LG2 (r = 0.7, P < 0.0001) (Fig. 8A,B).