The relatively high expression of IL3Rα in a number of leukaemias has presented a window of opportunity to develop new therapeutic approaches directed to IL3Rα such as monoclonal antibodies (MAbs)8,31,32, T cells engineered to express chimeric antigen receptors (CAR T cells)33 and toxin conjugates with IL-334–37. The gene discussed is IL3RA; the disease is leukemia.