Therefore, we sought to determine if there was a direct effect of Hh inhibition by vismodegib (GDC-0449), a pharmacological inhibitor of Hh-pathway and a clinically approved anticancer drug [18], on these GBM neurospheres in vitro irrespective of their relative endogenous levels of GLI1 mRNA expression. The gene discussed is GLI1; the disease is glioblastoma.