According to Rosa et al., the induction of periodontitis, per se, does not alter any of the inflammatory parameters, including IL-6 and IL-17, except for an increase in tumor necrosis factor-alpha in the bronchoalveolar lavage fluid in the COPD + periodontitis group compared to the COPD-only group in mice [135]. Here, TNF is linked to chronic obstructive pulmonary disease.