12-O-Tetradecanoylphorbol-13-acetate

12-O-Tetradecanoylphorbol-13-acetate (TPA), also commonly known as phorbol 12-myristate 13-acetate (PMA), is diester of phorbol and a potent tumor promoter often employed in biomedical research to activate the signal transduction enzyme protein kinase C (PKC). The effects of TPA on PKC results from its similarity to one of the natural activators of classic PKC isoforms, diacylglycerol. TPA is also being studied as a drug in the treatment of hematologic cancer. TPA is not to be confused with tPA, the former is a small molecule drug, whereas the latter is an enzyme. TPA was first found in the croton plant, a shrub found in Southeast Asia, exposure to which provokes a poison ivy-like rash. It is currently undergoing phase 1 clinical trials.