SERPINE1 and ovarian cancer: PAI-1 was robustly expressed in three out of six serous ovarian cancer cell lines (SKOV3ip1, TYK-nu, and HeyA8), while one cell line (OVCAR3) and two primary cultures of ovarian surface epithelial cells (OSE1 and 2) did not show detectable levels of PAI-1, and its receptor (uPAR) was expressed in all ovarian cancer cell lines tested (Figure 2A).