The study of principles governing the biosynthesis of mycotoxins by microscopic fungi, the determination of the sequence of reactions of biotransformation of mycotoxins in on animal organism, and the decoding of molecular and cellular mechanisms of their action are definitely the most important research trends in the area of mycotoxins. Considering that prevention of the formation of mycotoxins by producer fungi is the most effective measure of prophylaxis of alimentary mycotoxicoses in man and farm animals, one can fully appreciate the attention given by mycologists and biochemists to the peculiar features of mycotoxin biogenesis under various environmental conditions. It is likewise natural that all medical measures towards the removal or decreasing the extent of toxic action of mycotoxins upon men or animal should be founded upon thorough understanding of the metabolism of these foreign compounds and the mechanism of their action on the cellular and molecular levels.