SUV39H1 and neoplasm: We should keep in mind that mice deficient in SUV39H1 HMTs (which target lysine 9 of histone H3) have increased chromosomal instability and tumour risk (Peters et al, 2001) and another K9-H3 histone methyltransferase, RIZ1, undergoes CpG island hypermethylation-associated silencing in many tumour types (Esteller, 2005a).