<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A type 1 core O-glycan with potential immunotherapeutic property. Thomsen-Friedenreich (TF) antigen, a galactose disaccharide, is normally O-linked to serine or threonine residue of mucins (MUC1), a transmembrane glycoprotein overexpressed on epithelial cell surface of a variety of tumor cells. The expression of this antigen is associated with tumor cell adhesion, tissue invasion and aggressiveness. When administered in a vaccine formulation, TF antigen may stimulate a cytotoxic T cell response against tumors expressing TF epitope, which may result in a reduction in tumor size.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>