RAC1 and glioblastoma: Other Rho-family GTPases have not yet been examined, but RhoG merits consideration since it has been reported to stimulate membrane ruffling and macropinocyctosis (Ellerbroek et al., 2004) and can activate Rac1 in response to EGF or HGF in glioblastoma cells (Kwiatkowska et al., 2012).