Methylation is a biochemical process where a methyl group is added to a molecule, such as DNA or a protein. This addition can alter the molecule's function and activity, particularly in regulating gene expression. In the context of DNA, methylation can turn genes "on" or "off," affecting protein production. Elaboration: What is a methyl group? A methyl group consists of one carbon atom and three hydrogen atoms (CH3). How does it work? In DNA methylation, methyl groups are added to cytosine bases