PRDX3 and obesity due to melanocortin 4 receptor deficiency: Intracellular ROS not only damage cellular functions but also elicit signaling transduction in another fashion, indicating that these subpopulations of cells may alter their antioxidant capacity to maintain a redox balance.[19] A recent study reported that gastric cancer stem cells exhibited decreased mitochondrial ROS levels and increased drug resistance through peroxiredoxin 3 (PRDX3) expression.[20] In agreement with this, we identified that obesity‐associated tumor cells were associated with reduced mitochondrial ROS contents.