[5][6] CpG methylation is an epigenetic modification that is important for embryonic development, imprinting, and X-chromosome inactivation.

Studies in mice have demonstrated that DNA methylation is required for mammalian development.

This gene encodes a nuclear protein with similarity to DNA methyltransferases.

However, this protein does stimulate de novo methylation by DNA cytosine methyltransferase 3 alpha and it is thought to be required for the establishment of maternal genomic imprints.

This protein also mediates transcriptional repression through interaction with histone deacetylase 1.