GLI1 and brain neoplasm: Aberrant Hh signaling is found in the majority of the human cancers, including brain tumors [18], and is usually caused not only by mutations in Hh pathway components (e.g., receptors) but also by high expression of Hh ligands [13], Hh signaling, which plays an important role in stem cell renewal, is epigenetically regulated in CSCs mainly Gli transcription factors [46].