(A) Genes that were co-regulated with the MMPs that were upregulated in old gingival tissues (red diamond shapes) were analyzed using IPA. Highly expressed genes in old gingival tissue were filled with red, while lower expressed genes as green. Genes filled with white indicate no significant difference between young and old gingival tissues, but are incorporated into the network through relationships with other molecules. (B) The several genes (IL1, JNK, and PDGF BB complexes) that were associated with MMP regulation were identified in old gingival tissues using real-time PCR. Y, young gingival tissues; and O, old gingival tissues; n = 5; and *p < 0.05 versus the results from Y.