VTCN1 and central nervous system cancer: In the glioma microenvironment, FASL (CD95L) [20], programmed cell death ligand 1/2 (PD-L1/2) [21,22,23,24,25], galectin-1 [26], galectin-9 [27], HVEM [28], B7-H4 (B7x) [29], and CD70/gangliosides [30] expressed on glioma cells act as inhibitory ICMs.