<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A cancer vaccine consisting of ALVAC, a highly attenuated poxvirus strain derived from the canarypox virus. ALVAC-B7-CEA expresses carcinoembryonic antigen (CEA), a protein that is overexpressed by many tumor cells, and B7.1 (also known as CD80), the natural ligand for the T-cell antigen CD28, to augment the host immune response. This agent has been shown to stimulate a host immune response against tumor cells that express CEA. (NCI04)</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>