5-mC products are identified by growth arrest and DNA damage inducible alpha (GADD45A). GADD45A is responsible for recruitment of other repair factors to CpG sites for removal of methyl groups, and has been implicated as a necessary step in DNA demethylation by providing a link between epigenetics and DNA repair25, 26. GADD45A recruits Activation Induced Cytidine Deaminase (AID) and Apolipoprotein B mRNA Editing Enzyme, Catalytic polypeptide-like (APOBEC) proteins26, which deaminates 5-hmC to 5-hmU, generating a G-U DNA mismatch. This mismatch is removed by thymine DNA glycosylase (TDG) or methyl-binding protein 4 (MBD4). This cleavage activates the normal functions of the BER pathway including cleavage of the DNA backbone by AP-endonuclease and repair back to a non-methylated cytosine by XRCC-1, PARP-1, DNA ligase, and DNA polymerase27.