Herzog et al., during the 2015 annual meeting of the Society of Gynecologic Oncology, reported that the highest PD-1 expression rates among studied cancer types were in endometrial cancer (75.2%), epithelial ovarian cancer (66.9%), and cervical cancer (63.1%), and the highest PD-L1 expression rates were in ovarian sex cord-stromal tumors (75.0%), uterine sarcoma (46.3%), and endometrial cancer (25.2%) [47]. Here, PDCD1 is linked to endometrial cancer.