AKT1 and central nervous system cancer: A combination of erlotinib and sorafenib (an inhibitor of VEGFR2, PDGF, and RAF) had a synergistic effect on U87MG, LNZ308, and LN428 cells and on Glioma Stem Cells (GSC) by inhibiting the phosphorylation of ERK, AKT, and S6, decreasing the levels of nuclear β-catenin and PMK2, and inducing apoptosis and autophagy [205].