Since two selective ROCK inhibitors, Y-27632 and Fasudil, reportedly increase sphere formation and SOX2 expression by a glioblastoma cell line (U87-MG) and patient-derived glioblastoma xenoline (JX12) (ref. 41), Rho signaling downstream of p190 RhoGAP may be involved in PTPRZ-mediated regulation of glioma stem cell function. This evidence concerns the gene SOX2 and glioblastoma.