Differential DNA methylation at the promoter regions of 12 genes (DCC, KCNA3, KCNA2, RIMS2, HOXB7, PNOC, IRX1, JSRP1, TBX1, OPCML, CECR1, SCN4B) has been detected between periodontitis and clinically healthy tissues [41]. This evidence concerns the gene DCC and periodontitis.