As discussed, obesity fuels oxidative stress by increasing oxidant species; however, it also represses antioxidant defenses, particularly via the Keap1-Nrf2-ARE (Kelch-like ECH-associated protein 1–nuclear factor erythroid 2-related factor 2–antioxidant response element) signaling pathway. The gene discussed is KEAP1; the disease is obesity due to melanocortin 4 receptor deficiency.