It has been demonstrated in melanoma cell lines that the direct transcriptional target of TGF-β1-the Kruppel-like transcription factor GLI2 not only suppresses MITF through PKA/cAMP signaling 52 but also directly downregulates tyrosinase-related protein 2 (TRP2) by competitive inhibition of CREB 53. This evidence concerns the gene MITF and melanoma.