With both ALDH1A1 and ALDH3A1 deletion, NUP98-HOXA10 homeodomain fusion protein (NA10HD) can promote the development of leukemia with B220+ and varied levels of CD11b, though NA10HD alone only induces a rapid and marked expansion of HSC in vitro without malignant transformation [20, 29], strongly indicating the important role of ALDH in leukemia initiation. This evidence concerns the gene HOXA10 and leukemia.