The level of salivary defense proteins like immunoglobulin, molecular chaperone Hsp70, cystatin S, salivary amylase, calprotectin, hystatins, lysozyme, lactoferrine, defensins, peroxidases, prolin-rich proteins and mucins [38, 51, 52] may also have prognostic value related to the possible passing of gingivitis to periodontitis (where the latter is a more severe inflammation with irreversible destruction) [38, 120, 121]. This evidence concerns the gene PROS1 and periodontitis.