2F2I:
reference: Structural plasticity of the cyclic-cystine-knot framework: implications for biological activity and drug design., Clark RJ, Daly NL, Craik DJ, Biochem J. 2006 Feb 15;394(Pt 1):85-93. PMID: 16300479

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