CDKN2A and endometrial endometrioid carcinoma: Regarding p16 expression in endometrial tumors, focal/patchy pattern of p16 staining, was detected with both clones in 32/40 (80%) tested in endometrial endometrioid carcinomas (Figure 1 and Figure 2); the remaining endometrioid cases (8/40, 20%) exhibited 100% positivity; a strong and diffuse staining pattern was also observed in 30/30 (100%) uterine serous adenocarcinoma.