GSTM1 (Glutathione S-transferase M1)

Phase II hepatic detoxification enzyme that conjugates toxins with glutathione for elimination. Its genetic deletion (present in approximately 50% of the Caucasian population) reduces the ability to neutralise certain carcinogens and toxins, increasing skin sensitivity to irritants and UV rays. An example of genetic polymorphism explaining different individual skin responses to identical exposures.