GLI1 and glioblastoma: Hh pathway blockade in GBM neurospheres by cyclopamine reduces GLI1 mRNA expression, inhibits cell growth and promotes the formation of well-differentiated GFAP-positive neurospheres, indicative of mature glial cells [115], and downregulated the expression of stemness genes NANOG, OCT4, SOX2, NESTIN and BMI1 [101].