The ten-eleven translocation methylcytosine dioxygenase (TET1) is the first crucial step in DNA demethylation as this protein recognizes specific 5-mCs to be targeted for removal by DNA repair and conversion from 5-mC to 5-hydroxymethyl cytosine (5-hmC)23. 5-hmC can be further oxidized by TET proteins to 5-carboxycytosine (5-caC) and 5-formylcytosine (5-fmC); however, these derivatives are found less often in the genome, and their complete function is still being characterized24.