Since 2006, molecular studies (fusion genes AML1-ETO, PML-RARA, CBFβ-MYH11, MLL-AF4, MLL-AF9, and MLL-ENL, as well as FLT3-ITD and WT1 overexpression) have been performed in the central laboratory in Krakow as the standard diagnostic procedure in all pediatric patients with AML. This evidence concerns the gene CBFB and acute myeloid leukemia.