B-MYB antisense oligonucleotides inhibit proliferation of normal and transformed cell lines, while constitutive B-MYB expression allows BALB/c 3T3 fibroblasts to grow in low serum conditions and prevents cell cycle arrest and differentiation of M1 myeloid leukaemia cells treated with interleukin (IL)-6 [25-27]. This evidence concerns the gene MYBL2 and myeloid leukemia.