3MC2:
reference: The structure and evolution of the murine inhibitor of carbonic anhydrase: A member of the transferrin superfamily., Eckenroth BE, Mason AB, McDevitt ME, Lambert LA, Everse SJ, Protein Sci. 2010 Jun 23. PMID: 20572014

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