Rac GTPase-activating protein 1 (RacGAP1), one of the specific GTPase-activating proteins (RhoGAP), which stimulate the intrinsic GTPase activity of Rho proteins and restore them to the inactive state of binding to GDP [6], can regulate Rac1 and CDC42 proteins to drive tumor growth [7]. The gene discussed is RACGAP1; the disease is neoplasm.