PRRT2 and neoplasm: 12-O-Tetradecanoylphorbol 13-acetate (TPA; phorbol 12-myristate 13-acetate, PMA, 1), a tigliane diterpenoid also known as phorbol ester, is a potent tumor promoter that exerts its effects through the activation of protein kinase C (PKC) (Fig. 1) [6].