SHH and central nervous system cancer: Glioma-associated oncogene homolog 1 (Gli-1), originally identified in human glioma cells (Kinzler et al., 1987), is a zinc finger-containing transcription factor and the main nuclear mediator of the Sonic Hedgehog (SHH) signaling pathway (Dahmane et al., 2001; Infante et al., 2015) that regulate cell proliferation and differentiation during CNS development (Briscoe and Therond, 2013).