RARRES2 and diabetes mellitus: Adiponectin levels have been recently discussed to correlate with periodontal inflammation and diabetes (Purnamasari et al., 2019), while resistin has been argued to be a potential CP biomarker (Akram et al., 2017) and chemerin levels in gingival crevicular fluid and tears are potential biomarkers of inflammation in chronic periodontitis and type-2 diabetes mellitus (Patnaik et al., 2017).