<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A role used to imply the interaction or binding of an active ingredient of a drug/chemical agent at the molecular level with its target. When possible, the role value should reflect the direct alteration of function of a target molecule or complex. The domain and range for this role are 'Drug, Food, Chemical or Biomedical Material' and 'Biological Process', respectively.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>