A saturated derivative of sphingosine. As an inhibitor of protein kinase C (PKC), safingol competitively binds to the regulatory phorbol-binding domain of PKC, a kinase involved in tumorigenesis. This agent has been shown to act synergistically with other chemotherapeutic agents and may potentiate chemotherapy drug-induced apoptosis in vitro and in vivo. or A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called protein kinase inhibitors. Also called L-threo-dihydrosphingosine.