PIK3R1 and central nervous system cancer: Overexpression of miR-128 alone also enhanced TMZ-induced apoptotic death of glioma cells through direct modulation of key members of the mammalian target of rapamycin (mTOR) signaling, including mTOR, rapamycin-insensitive companion of mTOR, insulin-like growth factor 1 (IGF-1), and phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1) [108].