Similarly, Bertoldi et al. [23] demonstrated that salivary levels of MMP-8, IL-1β, IL-4, IL-8, and IL-10 significantly differ between healthy individuals, untreated periodontitis patients, and those post-treatment, highlighting the potential of these biomarkers for non-invasive diagnosis and monitoring of periodontal disease progression and treatment response. The gene discussed is IL4; the disease is periodontitis.