As shown in Table II, 2 of 30 cases (6.7%) of benign cystadenomas had high levels of OCT4 protein, whereas 14 of 30 cases (46.7%) of borderline tumors and 65 of 99 cases of carcinoma (65.7%) showed high expression of OCT4 protein. This evidence concerns the gene POU5F1 and cystadenoma.