Moreover, clinical trials also show the increased number of peripheral and local TH1 and TH17 lymphocytes, the essential TH cell populations in nuclear factor kappa B (NF-κB)-dependent pathogenesis of periodontitis, as well as promoted the expression level of T-bet, IFN-γ, and IL-17A in chronic periodontitis (Chen et al., 2016; Monasterio et al., 2019). Here, IFNG is linked to periodontitis.