L-threo-PPMP is an inhibitor of glucosylceramide synthetase and isomer of D-threo-PPMP (Item No. 22677).1 It inhibits the growth of MCF-7, MDA-MB-468, and SK-BR-3 breast cancer cells (ED50s = 4, 7, and 6 μM, respectively) through damage of cell organelle membranes, increasing ceramide concentration, and induction of apoptosis. [Matreya, LLC. Catalog No. 1868]WARNING This product is not for human or veterinary use.