Both, transgenic [49] and knock-in [78] mouse models expressing FLT3 ITD in the haematopoietic compartment revealed that FLT3 ITD mutations enhance survival and proliferation of lymphoid and myeloid progenitor cells and induced in particular a myeloproliferative syndrome [79], resembling chronic myelomonocytic leukaemia [78]. The gene discussed is FLT3; the disease is chronic myelomonocytic leukemia.