Although DNA hypo-methylation in vitro and higher levels of DNA methylation in vivo as epigenetic alterations in AD have been reported (Sanchez-Mut and Graff, 2015), roles of target genes of PAX3 and PAX7 such as Cdc20 and Id3 have not been researched in neither AD nor MDD (Diao et al., 2012). This evidence concerns the gene ID3 and major depressive disorder.