DNMT1 and diabetes mellitus: Our study is focused on crosstalk between H3K9 methylation and DNA methylation-hydroxymethylation in Rac1 transcriptional activation in diabetes, however, we recognize that methylation of lysine, other than K9 of histone 3, could be helping in recruiting Dnmt1 and increasing Rac1 transcription; activation of an enzyme responsible for methylation of lysine 27 of histone 3, Enhancer of Zeste homolog 2 (Ezh2), in diabetes is also associated with active DNA methylation and transcriptional activation of retinal MMP-938, and role of Ezh2 in Rac1 transcriptional activation remains a possibility.