In a model of t (8;21) AML in which retrovirus expression KIT N822 and RUNX1-RUNX1T1 were co-transduced, expression of the KIT mutant alone led to MPD, but overt leukemia was observed when KITN822 was expressed in conjunction with RUNX1-RUNX1T1 (87). Here, RUNX1 is linked to leukemia.