<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A semi-synthetic triterpene glycoside, derived from the naturally occurring saponins. GPI-0100 functions as an adjuvant when given as part of a vaccine preparation to improve the immunogenicity of antigens such as proteins, carbohydrates. GPI-0100 containing vaccines have been used with both viral and tumor antigens to elicit a Type 1 helper T cell response for those diseases in which a cytotoxic T lymphocyte (CTL) response is desired.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>