T-ALL patients that correspond to the HOXA group are characterized by high levels of expression of HOXA5, HOXA7 and HOXA9 genes.13, 14 Staining of the central-posterior part of developing limbs observed in LMO2 +1 enhancer transgenic embryos was similar to the expression pattern of central-posterior HOXA genes (including HOXA5, HOXA7 and HOXA9) during early development. This evidence concerns the gene HOXA5 and acute lymphoblastic leukemia.