MW, Mann-Whitney U test; NOM, normal oral mucosa; K, Kruskal-Wallis test; OSCC, oral squamous cell carcinoma; OSF, oral submucous fibrosis; TGF-β1, transforming growth factor-beta 1; TGF-β3, transforming growth factor-beta 3. The gene discussed is TGFB1; the disease is oral cavity squamous cell carcinoma.