1RCB:
reference: Crystal structure of human recombinant interleukin-4 at 2.25 A resolution., Wlodaver A, Pavlovsky A, Gustchina A, FEBS Lett 1992 Aug 31;309(1):59-64. PMID: 1511746

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).