POU5F1 and cystadenocarcinoma: Low levels of OCT4 protein were detected in 8 of the 11 clear cell carcinomas (72.7%); however, high levels of OCT4 protein were examined in 5 of the 8 endometrioid adenocarcinoma (62.5%), 4 of the 6 mucinous cystadenocarcinoma (66.7%) and 53 of the 74 (71.6%) serous cystadenocarcinoma cases (Table III and Fig. 1Cc–f).