CXCR4 and leukemia: Multiple antagonists targeting CXCR4 have been developed for uses in leukemia treatments, which can be divided into three categories: (1) chemical molecules, representatives are AMD3100 and its derivatives AMD3465 and AMD11070, they are originally developed for HIV treatment16, 17, 18, 19, 20, 21, 22; (2) peptides obtained from horseshoe crabs15, 16, 17, 18, representatives are T140 and its derivatives TC14012 and TN14003, and RCP168 derived from viral macrophage inflammatory protein II23; (3) antibodies such as 12G5 and BMS-936564/MDX-133811, 24.