<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>Receptor Genes encode cell surface or cytoplasmic receptor proteins that each bind to specific signaling factors (such as a hormone, antigen, or neurotransmitter) causing a conformational and functional change in the ligand-bound receptor, altering its interaction with target molecules and leading to changes in cellular physiology through modification of the activity of one or more signal transduction pathways.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>