PTGS1 and neoplasm: Sulindac sulfone has been shown by several investigators to inhibit tumor cell growth and induce apoptosis in vitro in a number of tumor cell lines of diverse histological origin despite its lack of COX-1 and COX-2 inhibitory activity and can inhibit chemical-induced carcinogenesis of the colon, mammary glands, lung and bladder [18,30,34,48,49,50,51,52,53].