On the other hand, it is known that the MMP-8′s up-regulator’s IL-1β mRNA [19,22] and activator MMP-7 mRNA [29] and potential endogenous inhibitor TIMP-1 mRNA can be de novo transcriptionally up-regulated in the diseased periodontitis gingivae [4,7,8,30,31]. Here, TIMP1 is linked to periodontitis.