<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>The identifier used by NCI's Cancer.gov Web site to retrieve PDQ Clinical Trials data for open trials involving specific clinical trials agents. While the identifier is the same for both open and closed trials two properties are used to support requirements of the current browser interface, as well as the possibility of providing values only where trials will be retrieved.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>