We previously reported that GSPT1 is a novel downstream target of RAC1 [6], which is a member of the Rho-family small GTPases and has been reported as a tumor-driving and -promoting molecule [7], and that depletion of GSPT1 and RAC1 induced delayed proliferation of glioblastoma (LN229) cells and primary astrocytes [6]. The gene discussed is GSPT1; the disease is glioblastoma.