Thus, as in the p16p19−/−; Kras(G12V) model, in the MLL-AF9 model, systemic development of myeloid leukemia in recipient mice occurs following extramedullary tumor formation, with fluorescently marked tumor cells migrating from the injection site in the hindlimb muscle to the BM and spleen. The gene discussed is MLLT3; the disease is neoplasm.