The repression cluster could be further separated into genes repressed in both MLL-ENL and MOZ-TIF2 after progression to frank leukaemia (Klf1, Gata2, Gfi1b, Zfpm1/Fog), repression in MOZ-TIF2 only (Cebpe, Fli1), repression in MLL-ENL only (Tal1, Eto2, Runx1) and more variable patterns (Cebpa, Ets1, Meis1, Pbx1). Here, PBX1 is linked to leukemia.