Oltipraz is an organosulfur compound belonging to the dithiolethione class. It acts as a schistosomicide and has been shown in rodent models to inhibit the formation of cancers in the bladder, blood, colon, kidney, liver, lung, pancreas, stomach, and trachea, skin, and mammary tissue. Oltipraz and other 1,2-dithiole-3-thiones inactivate protein tyrosine phosphatases under physiologically-relevant conditions. Clinical trials of oltipraz have failed to demonstrate efficacy and have shown significant side effects, including neurotoxicity and gastrointestinal toxicity.