GLI1 and skin basal cell carcinoma: BCC is caused by aberrant activation of the hedgehog/glioma-associated oncogene pathway, mostly due to genetic inactivation of the protein patched homolog (PTCH) gene or activation of “smoothened.” Recent studies have shown that IMQ mechanisms of action include the stimulation of adenosine receptor/protein kinase A-mediated GLI phosphorylation, resulting in the inhibition of hedgehog signaling [68].