<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A type of lipid (fat) found in the membranes of cells and the covers of nerves. Some ceramides are important in signal transduction (the process by which a cell responds to substances in its environment) and may cause some types of cells to die. Ceramides are being studied in the treatment of cancer.</n0:def-definition><n0:def-source>NCI-GLOSS</n0:def-source></n0:ComplexDefinition>
<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>One of a number of a class of sphingolipids, N-acyl derivatives with long chains. Ceramide is the core molecule for the synthesis of sphingomyelin, an essential lipid for myelination and neurotransmission; it may function as a second messenger to stimulate differentiation, inhibit proliferation, and induce apoptosis. (NCI04)</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>