High expression of HOXA9, HOXA10, and MEIS1 is considered to be a general hallmark of all MLL-FP leukemias, but a detailed analysis of patient expression data show that many t(4;11) leukemias do not express high levels of these genes (Stam et al., 2010; Trentin et al., 2009), indicating that other additional targets are likely to have an important role in t(4;11) leukemogenesis. Here, HOXA9 is linked to leukemia.