The adoptive transfer (or BMT) of ALHBH5-deficient immune population (donor: CD45.2+Lin−) co-cultured with MLL-AF9 cells into recipient (CD45.1) mice significantly delayed leukaemia progression and prolonged survival with decreased splenomegaly, white blood cells count and immature blast cell (CD11b (Mac-1)+ c-Kit+) populations. The gene discussed is ITGAM; the disease is Splenomegaly.