C8 D-threo Ceramide is a bioactive sphingolipid and cell-permeable analog of naturally occurring ceramides. It is cytotoxic to U937 cells (IC50 = 17 μM) and induces nuclear DNA fragmentation 5- to 6-fold more potently than C8 ceramide . C8 D-threo Ceramide is a substrate for E. coli diacylglycerol kinase. It activates ceramide-activated protein kinase (CAPK) in U937 cells. C8 D-threo Ceramide also enhances V. cholerae cytolysin pore formation in liposome lipid membranes, as measured by calcein release, with a 50% release dose (RD50) value of ~5 μg/ml.