S100A9 and lip and oral cavity carcinoma: In addition, we determined whether these carcinomas overexpress PCNA and p53 protein, two prognostic factors in human oral cancers.34,35 The p53 tumor suppressor gene is mutated in approximately 50% of all human cancers, including oral-esophageal cancers36 and divergent carcinogenic pathways mediated separately by NF-κB and p53 were reported in oral cancer.37 Using IHC we examined expression of seven markers: PCNA, p53, and five S100A8—NF-κB signaling markers (S100A8, S100A9, RAGE, NF-κBp65 and cyclin D1).