1ITL:
reference: Human interleukin 4. The solution structure of a four-helix bundle protein., Smith LJ, Redfield C, Boyd J, Lawrence GM, Edwards RG, Smith RA, Dobson CM, J Mol Biol 1992 Apr 20;224(4):899-904. PMID: 1569578

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