[en] Glutathione (GSH) and synthetic aminothiols, such as N-acetylcysteine (NAC), play an important role as inhibitors of mutagenesis and carcinogenesis. The present paper updates the studies carried out in the authors' laboratories, which are discussed according to a mechanistic approach. In Table 1, reporting the classification of inhibitors of mutagenesis and carcinogenesis proposed by De Flora and Ramal, the arrows indicate the mechanisms that they have investigated so far in the case of aminothiols. 38 refs., 6 figs., 1 tab