<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>Any of the recombinant form of the naturally occurring Interleukin-1 Receptor Antagonist that blocks the biological activity of Interleukin-1 by binding to the Interleukin-1 receptor.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>