RAC1 and central nervous system cancer: While the low expression of ARHGDIA in human glioma attenuates the inhibition effects of the GDP-bound inactive Rho family protein, and the GTP-bound form of Rho GTPases (Cdc42, Rac1, and Rho) is activated to switch on downstream pathways by acting on theirs effectors including improving phosphorylated Akt (Fig. 7b), which finally promotes cancer biological process including cell proliferation, cell cycle progression, and cell migration.