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Epigenetics is a discipline that studies potentially reversible heritable changes in gene expression with no structural modifications in the DNA sequence. The epigenetic machinery is integrated by a cluster of interconnected elements that in a coordinated manner contribute to regulating gene expression at the transcriptional and posttranscriptional level. Classical epigenetic mechanisms include DNA methylation, histone modifications, and microRNA (miRNA) regulation. Canonical DNA methyltransferases (DNMTs) (DNMT1, DNMT3A, DNMT3B) are responsible for maintaining DNA methylation patterns, whereas DNA demethylation can be produced by at least three enzyme families: (i) the ten-eleven translocation (TET) family, mediating the conversion of 5mC into 5hmC; (ii) the AID/APOBEC family, acting as mediators of 5mC or 5hmC deamination; and (iii) the BER (base excision repair) glycosylase family involved …