Scheme showing the structure of cytosine, 5-methylcytosine, and 5-hydroxymethylcytosine. Adding a methyl group to the DNA base cytosine represses gene expression in mammalian cells. To remove the ...

DNA is the blueprint for life, influencing everything about us—including our health. We know that our genes, the genetic “words” that encode proteins, play a major role in health and disease. But the ...