iant structure was target-designed, not by trial and error. OH2 Laboratories, LLC Confidential and Proprietary EFTA00586589 Coding CXCR4QTY from CXCR4 TMHMM posteror probabilities for WI 1.2 7 distinctive Trans membrane helices 0 Trans membrane helices! I 0.8 0.6 0.4 0.2 0 1.2 0.8 0.