Methylation of lysine can promote transcriptional activation or repression and is critical in regulating histone function. Lysine residues can be mono-, di-, or tri-methylated.1 SET8 selectively mono-methylates histone H4 at lysine 20, an event proven to have an important role in chromatin structure and transcriptional activation.2,3 SET8 is also a novel regulator of p53, mono-methylating lysine 382 of the tumor suppressor.4 SET8’s ability to suppress p53 transcriptional activity implies that it may play a significant role in tumorigenesis.WARNING This product is not for human or veterinary use.