Treatment with either a flavone or benz(alpha)anthracene before the addition of a potent carcinogen, benzo(alpha)pyrene or 3-methylcholanthrene, enhanced the transformation of Syrian hamster cells that are seeded in order to form colonies. 7,8-benzoflavone and benz(alpha)anthracene prevented the cytotoxicity by the carcinogens, while 5,6-benzoflavone did not. The results clearly indicate that i...