Beware of a new carcinogenic risk: promotion of promoters

Restricting the evaluation of carcinogenic risk to genotoxicity or mutagenicity tests, as recently recommended by some researchers, is a hazardous operation, since the carcinogenic process involves a complex sequence of events in which no simple, necessary and sufficient condition is known for either the occurrence or non-occurrence of a cancer. None of the available tests exhibit a generalizable meaning, while none of the carcinogenic process phases should be neglected in prediction studies. In particular, ignoring promoter action and progression or proliferation, as well as targets specificity and other points, should lead to an underestimation of the actual risk.