CDK4 and benign neoplasm: Negative expression in both p16 and CDK4 was observed in a higher proportion of benign tumors (65.0%) as compared to malignant (26.2%) and intermediate cases (37.5%) while a higher proportion of malignant (57.1%) as compared to benign (35.0%) and intermediate cases (37.5%) had positive expression in either p16 or CDK4; positive expression in both p16 and CDK4 was observed in a higher proportion of intermediate (25.0%) cases as compared to benign (0.0%) and malignant (16.7%).