TP53 and carcinoma: Based on the morphologic findings for P53 and CK20 staining, the sensitivity, specificity, and positive and negative predictive values of CK20 staining compared to the morphological criteria for the diagnosis of high- and low-grade carcinomas were 44%, 92%, 84.6%, and 62.2%,, respectively, while these findings for P53 were 48%, 80%, 70.5%, and 60.6%, respectively (Table 2).