CDKN2A and periodontitis: We found that 11 CRGs expression were decresed in periodontitis, including SLC31A1, LIPT1, NFE2L2, FDX1, LIAS, ATP7A, DLD, MTF1, DLAT, DBT and PDHB, while 4 CRGs expression were increased in periodontitis, including NLRP3, GLS, CDKN2A and DLST.