Park JK, et al. - Immunohistochemical analysis of PSF3 (Partner of SLD Five 3) expression was performed to examine whether PSF3 could serve as a useful biomarker for endometrial carcinomas. Researchers reported that PSF3-positive cells were selectively found in tumor cells. In addition, Ki-67-positive cells were found in tumor stromal cells. It was observed that PSF3 immunostaining was valuable as a histopathological marker for differential diagnosis between atypical hyperplasia (AH) and endometrial carcinomas (ECs), for tumor histological grading and for determining a patient's prognosis. The study findings suggested that PSF3 could play a crucial role in tumor progression in EC.