Interestingly, Nalm-6 ALL cells expressed BMP4, but not other related BMP ligands such as BMP2, BMP6 or BMP7 (Table 2), and neutralization of BMP4 in ALL-derived CM reduced (by 40–50%) the accumulation of CD1a− CD14+ cells and increased the generation of CD1ahi CD14−/lo DCs (data not shown; manuscript in preparation). This evidence concerns the gene BMP4 and acute lymphoblastic leukemia.