Our intriguing finding, demonstrating that exogenous cholesterol increases NADPH levels in breast cancer cells in an ERRα-dependent manner, is physiologically relevant, as ERRα is known to be involved in NADPH generation and ROS elimination via the induction of key enzymes involved in ROS detoxification, such as SOD2 and GSTM1, which have been identified as target genes of ERRα [20]. The gene discussed is GSTM1; the disease is breast carcinoma.