Therefore, in addition to the regulation of formation of genotoxic PAH metabolites, activation of the AhR by PAHs can be associated with further non-genotoxic mechanisms of action of PAHs, including e.g.: perturbation of cell cycle progression, cell proliferation and programmed cell death [27], deregulation of action of hormones and/or their metabolism (including e.g. increased catabolism of steroid hormones) [131], as well as deregulation of numerous genes linked with cancer development [132]. This evidence concerns the gene AHR and cancer.