'Cryptic' mutagens and carcinogenicity

CASE, the Computer Automated Structure Evaluation method, predicts that a fraction of the chemicals identified as 'non-genotoxic' carcinogens, i.e. rodent carcinogens which are not mutagenic in Salmonella, are, in fact, potential Salmonella mutagens. These chemicals are termed 'cryptic mutagens', i.e. agents that possess structural determinants which endow them with potential mutagenicity. Even though this potential is not expressed in Salmonella, it may be expressed in other systems such as in the mutagenic activation of oncogenes.