Abstract
• Fungi were isolated from a house associated with four leukemic patients from three families because of the possibility that mycotoxin-producing strains might be present. Extracts of several of the isolated fungal species produced toxic effects in one or more species of animals. Aflatoxin-producing Aspergillus parasiticus was isolated. Similar genera were isolated from non-leukemia-associated houses with the exception of Trichoderma, Verticillium, and Monotospora. We believe that certain mycotoxins may be related to pathogenesis of leukemia, possibly as an expression of their immunosuppressive effects.