94). In line with these findings, NANOG has been shown to act as a mediator of the HH-GLI signalling in regulating in vivo growth of glioblastoma CSCs (Ref. 95). Similarly, HH-GLI signalling regulates the expression of SOX2 in neural stem cells and medulloblastoma (Refs 96, 97). Recently, we showed that both GLI1 and GLI2 bind to SOX2 promoter in melanoma cells and that SOX2 function is required for HH-induced self-renewal of melanoma CSCs (Ref. 98). This evidence concerns the gene GLI2 and medulloblastoma.