To study the mechanism(s) of turmeric-mediated chemoprevention and to compare the chemopreventive efficacy of turmeric/curcumin(s) against benzo[a]pyrene (B(a)P) and 4-methylnitrosamino-1-(3-pyridyl)-1-butanone (NNK, a tobacco-specific carcinogen), the effects of turmeric/curcumin (C),