NPM1 and leukemia: Acute myelogenous ‘M5-like’ leukaemia was primarily based in this study on the detection of monocyte-like cell subpopulations expressing CD14 and CD64 and lack of immaturity markers such as CD34 and CD117, though the latter two markers among M5 leukaemias have been cited in the literature.40 A number of mutations have been associated with M5, notably the MLL containing t(9;11)47 and also forms with NPM1 mutations,44 although both mutations are also seen in other AML types.44