CDKN2A and neoplasm: Although there was no significant change in p16(INK4A) expression ratios (primary tumor compared to corresponding adjacent mucosa from the same patient) between HPV− and HPV+ OPSCC (Wilcoxon rank sum test P = 0.3), we observed a significant increase in p14(ARF) expression (tumor:normal ratio) in HPV+ compared to HPV− OPSCC (P = 0.004).