SMO and skin basal cell carcinoma: Protein kinase A (PKA) activation by cAMP agonist forskolin inhibited BCC growth, particularly drug resistant BCC for Smo inhibitors, which was performed and evaluated in tamoxifen-induced 30-day-old postnatal mice which were born from male K14-CreERT2 crossed with female homozygous R26-SmoM2 (Makinodan & Marneros, 2012).