On this basis, it is proposed an innovative approach to cancer chemotherapy through inhibition of one of the protective mechanisms against apoptosis, ie the increase in ALDH activity than cancer cells put involved in overcoming the lethal effects of damaged roads. ALDHs of inhibitors they may have immediate application as anti -cancer in vivo? The limited experimental data obtained so far on human tumor xenografts in immunodeficient mice and the absence of data on the in vivo toxicology do not allow direct passage to clinical trials. Indeed, some members of the ALDH superfamily are expressed constitutively in some vital organs they protect against the deleterious effects of xenobiotics and adverse endogenous metabolites. Consequently, if ALDHs should be inhibited, of the collateral damages for the normal cells could occur. However, when normal cells have not undergone deleterious exposure, these harmful metabolites are not or in very small quantities, which do not require high levels of ALDH activity, and therefore without harm to the inhibition of cell of these enzymes.