CHEK2 and neoplasm: Consistent with the INPP4B tumor suppressor function, the tumorigenic markers MAPK, SRC, and SNAI2 were elevated (Figure 1a) [36,37], and the tumor suppressor proteins RB1, BRCA1, and CHEK2 [38,39,40] were decreased in the cells treated with siRNA targeting INPP4B.