5-hmC is a DNA modification which results from the enzymatic conversion of 5-methylcytosine into 5-hydroxymethylcytosine by the TET family of oxygenases. Preliminary results indicate that 5-hmC may have important roles distinct from 5-methylcytosine (5-mC). Although its precise role has still to be shown, early evidence suggests a few putative mechanisms that could have big implications in epigenetics.
