Glioma-associated oncogene 1 (Gli1) is a transcription factor within the DNA-binding zinc-finger protein family. The Sonic Hedgehog signaling pathway (SHH), which assists in embryonic development and maintaining stem cell populations in adults, activates the Gli1 protein. In the SHH Pathway, the hedgehog ligand binds to patched transmembrane protein receptor (PTC). PTC is an inhibitor of SMO, a protein receptor, and when the hedgehog ligand is present, SMO is not inhibited.
