The Chemoprevention Branch is testing dozens of candidate chemopreventive compounds in the following rodent model carcinogenesis systems: mouse skin papillomas, DMBA/TPA induced, rat mammary adenocarcinoma, DMBA and MNU induced, hamster tracheal squamous cell carcinoma, MNU induced, and lung adenocarcinoma, DEN induced, rat and mouse colon adenocarcinoma, AOM and MAM acetate induced, respectively, and mouse bladder carcinoma, hydroxy BBN induced. Significant chemopreventive (i.e., anticancer) effects have been produced with 4-hydroxy-phenylretinamide, difluoromethylornithine, piroxicam, oltipraz (a dithiolthione), calcium glucarate, N-acetylcysteine, beta-carotene, ibuprofen, dehydroepiandrosterone (DHEA) and a 16-fluoro DHEA analog, 8354, tamoxifen, glycyrrhetinic acid, molybdate, selenite, curcumin, and fumaric acid.