Aflatoxin is a byproduct of mold that can cause DNA damage. With prolonged exposure to aflatoxin, cells accumulate DNA mutations and thus are at increased risk of developing into cancer cells.A lot is known about the mechanisms of activation and action of aflatoxin. It forms a reactive epoxide intermediate, which then forms a covalent bond to the N7 atom of guanine in site-specific sequences within critical target genes leading to mutations, altered function, loss of function of those genes. p53 is a major target for aflatoxin.
Aflatoxin is probably the best example of a carcinogen, a human carcinogen that targets p53. There are multiple hot spots in the p53 gene targeted by different types of carcinogens. Aflatoxin targets a guanine in codon 249 in the p53 gene.