4HCS:
reference: Structural insight into the evolution of a new chemokine family from zebrafish., Rajasekaran D, Fan C, Meng W, Pflugrath JW, J Lolis E, Proteins. 2013 Jul 31. doi: 10.1002/prot.24380. PMID: 23900850

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