STAT1 and ovarian cancer: We found that the enhanced phosphor-STAT1 was neither observed in the wild type normal ovarian epithelial HOSE-E6E7 cells, nor in the wild type ovarian cancer cells (OVCA429), but only found in BRCA1-mutant cell lines (HOSE-642, HOSE-636, and UWB1) (Fig. 4A).