AKR1C1 and melanoma: To verify the role of AKRs enzymatic activity in lipid peroxide demolition in melanoma cells, resistant cell lines were exposed 24 or 48 h to ERA, in presence or absence of the AKR1C1 ÷ 3 pan inhibitor medroxyprogesterone33 (MPA; 10 μM), and cell viability was evaluated as reported above.