Furthermore, TNF-α levels in the gingival crevicular fluids were positively associated with PI, GI, and PPD (p < 0.001) in HD patients, and similar positive correlations were also detected between IL-8, and PI (p = 0.002), GI (p = 0.002), and PPD (p = 0.012) [53]. Here, TNF is linked to Huntington disease.