Nair et al., [28], Wankhede and Dhadse, [29], Nainee et al., [30], Kalate et al., [32], Althebeti et al., [33], Mitani et al., [34], Himani et al., [ 35], Nagireddy et al., [36], Shaker et al., [37] and Vernal et al., [39] showed in their investigations that the levels of the IL-23/IL-17 axis in GCF were increased and positively correlated with the progress and severity of periodontal disease (GI, PD, CAL). This evidence concerns the gene IL17A and periodontal disorder.