PER1 and ovarian endometrioid adenocarcinoma: We further analyzed the Oncomine data and found low expression of PER1 in mucinous ovarian adenocarcinoma, clear cell ovarian adenocarcinoma, serous ovarian adenocarcinoma, ovarian endometrioid adenocarcinoma, and ovarian endometrioid cystadenocarcinoma compared with normal ovarian tissue (Figure 1C).