Procarcinogens require metabolic activation by cellular enzymes to form the ultimate carcinogenic species that covalently bind to DNA
Most procarcinogens are metabolized to carcinogenic compounds by cytochrome P450 enzymes in the smooth endoplasmic reticulum and are referred to as microsomal
Example
Benzo[a]pyrene & AflatoxinB1
Procarcinogen (X bind to DNA) --> Proximate carcinogen (Intermediate metabolites) --> Ultimate carcinogen (Reactive metabolites that bind DNA)
