<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>Formulated therapeutic proteins that are either isolated from endogenous sources or manufactured in a laboratory. Growth factors bind to specific receptors expressed by various cell types, thereby stimulating cell differentiation and/or proliferation. (NCI04)</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>