One of molecular consequences of proteasome inhibition is the degradation of the NF-kB regulator IB resulting in the suppression of NF-kB activity and the accumulation of the two tumor-suppressor proteins p27 KIPI and p53 [116,117,118].Preclinical data from pediatric studies showed increased proteasome activity and NFkB levels in AML blasts [118,119]. This evidence concerns the gene NFKB1 and acute myeloid leukemia.