Results: A significant decrease in CD57 labeling index was seen from well-differentiated squamous cell carcinoma (16.63 ± 2.33) to poorly differentiated squamous cell carcinoma (5.53 ± 1.20) whereas the significant increase in PCNA labeling index was noted from well-differentiated squamous cell carcinoma (45.88 ± 2.20), followed by moderately differentiated and poorly differentiated squamous cell carcinoma (72.77 ± 4.35). The gene discussed is PCNA; the disease is squamous cell carcinoma.