INPP4B and central nervous system cancer: To investigate whether INPP4B restrained PD-L1 expression by glioma cells through interfering with PI3K/AKT signaling, U87 cells were transfected with siRNA-Scramble or siRNA-INPP4B for 48 h with or without LY294002, and surface PD-L1 was analyzed by flow cytometry.