<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>Recombinant therapeutic agents chemically identical to or similar to endogenous nerve growth factors (neurotrophins) that play vital roles in the development of the nervous system. Brain-derived growth factors may also regulate hematopoiesis and immune cell function. Examples of brain-derived growth factors include nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF). (NCI04)</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>