Elevated levels of proteolytic enzymes (P. gingivalis gingipain, human neutrophil elastase, matrix metalloproteinases, total proteolytic activity), cytokines (interleukin-1β), and chemokines (MDC, MIP-1α, MCP-2) have been found in tissue and saliva samples of periodontitis patients in comparison to their controls [16,17,18,19,20,21]. This evidence concerns the gene CCL22 and periodontitis.