Transient transfection of PGIS into MCF-7 cells exposed to sulindac increased cell viability by 50% and exposure to carbaprostacyclin protected against sulindac sulfone induced apoptosis in CCRF-CEM cells.Expression of PGIS is correlated with a reduced patient survival and protects against cell death in vitro, suggesting that PGIS is a potential therapeutic target in breast cancer. This evidence concerns the gene PTGIS and breast cancer.