BMS‐936564, a pioneering IgG4 fully human monoclonal antibody, exhibits selective binding affinity to the second extracellular loop of CXCR4. This interaction, pivotal in the context of acute myelogenous leukaemia, instigates a substantial elevation, ultimately triggering apoptosis in tumour cells. The gene discussed is CXCR4; the disease is acute myeloid leukemia.