Any of a group of secondary metabolites produced by the common molds Aspergillus flavus and A. parasiticus that cause a toxic response in vertebrates when introduced in low concentration by a natural route. The group constitutes a type of mycotoxin. Discovered in 1960 after a massive poisoning of turkey poults fed moldy peanut meal, aflatoxin has become the focus of a highly interdisciplinary research field involving chemists, mycologists, veterinarians, agriculturalists, toxicologists, and other basic and applied scientists.