Among haematopoietic tumours, aberrant methylation of promoter-associated CpG islands (CGIs) in oestrogen receptor, p16INK4A, p15INK4B, p73, p57KIP2 and DAP kinase has been observed in acute lymphocytic leukaemia (ALL), acute myeloid leukaemia (AML), malignant lymphoma and multiple myeloma (Herman et al, 1997; Katzenellenbogen et al, 1999; Garcia-Manero et al, 2002a, 2002b; Li et al, 2002). The gene discussed is CDKN2A; the disease is acute myeloid leukemia.