GLI is implicated in the regulation of mammalian tumorigenesis by inducing factors associated with tumor stem cells, promoting cancer cell proliferation through cell cycle-related proteins, inhibiting apoptosis via direct binding to anti-apoptotic promoters, and upregulating Smad-interacting protein-1 (Sip1), which drives epithelial-mesenchymal transition (EMT). Here, GLI1 is linked to cancer.