HOXA9 and acute myeloid leukemia: Indeed, through interaction with SMAD4, HOXA9 (as well as the oncogenic fusion protein NUP98-HOXA9) was removed from DNA [253] and sequestrated in the cytoplasm to protect normal hematopoietic stem cells and progenitor cell (HSPC) transformation by HOXA9 or NUP98-HOXA9, as evidenced in a mouse model of AML [254].