Croce and colleagues have shown that miR-155 targets HDAC4, leading to its underexpression, and that the ectopic expression of HDAC4 in diffuse large B-cell lymphoma cells inhibits miR-155-induced proliferation and increases the apoptosis of the cells.36 The elucidation of the molecular mechanisms involved in the repression of HDAC7 in pro-B-ALL and B-cell lymphoma is a current focus of study in our laboratory. This evidence concerns the gene HDAC4 and acute lymphoblastic leukemia.