IL17A and chronic periodontitis: Although data derived from GCF levels of various inflammatory mediators like cytokines/chemokines in aggressive periodontitis subjects and chronic periodontitis subjects differ, many studies have found a significant increase in levels of pro-inflammatory cytokine/chemokines such as IL-6, IL-8, IL-1β, IL-17, TNF-α, and IL-29 in aggressive periodontitis compared to chronic periodontitis cases [23-27].