CDKN2A and acute lymphoblastic leukemia: Selective p15INK4b promoter hypermethylation, without p16INK4a alterations, is observed in acute myeloid leukemia (AML), myelodysplastic syndrome and ALL (140, 142–146), whereas Burkitt’s lymphoma and Hodgkin’s lymphoma present p16INK4a hypermethylation (140, 141, 147–150).