Interestingly, in a clinical phase II study in patients with advanced malignant melanoma, it was noted that the response to monotherapy with nitrosourea fotemustine could have two results that the authors correlated with the expression of different systems of glutathione reductase/glutaredoxin; i) sensibility to the drug, including full recovery, or ii) no response with no change in tumour size [223]. The gene discussed is GLRX; the disease is neoplasm.