EHMT1 is a histone methyltransferase which specifically methylates histone H3 on lysine 9. H3K9 methylation represents a marker for epigenetic transcriptional repression. This repression is established by recruiting HP1 proteins to the methylated histone. H3K9 methylation may contribute to silencing of MYC and E2F responsive genes and plays a role in murine embryogenesis.