A radical opposition in body weight control

Reactive oxygen species (ROS) are generally considered to be detrimental for health because of their association with a wide variety of diseases including, but not limited to type 2 diabetes, cardiovascular complications and cancer; as such, they have been considered to be undesirable by‐products of aerobic metabolism. This concept has led to the widespread use of antioxidant food supplements to promote health as well as to prevent and even treat certain disease types. In recent years, however our view on ROS and antioxidants has shifted, as more and more evidence is accumulating that ROS are actually fundamental signalling molecules inmany cellular processes and that excessive ROS scavenging may have damaging side effects. The study by Chang et al (2013) in this issue provides additional evidence for this notion as it aims to unravel the role of ROS signalling in adipogenesis. It is well accepted that ROS signalling controls fat cell formation in vitro; the pathways that govern this process, however, are still incompletely understood. In the current study, the authors show that glutathione peroxidase 7 (GPx7 or NPGx) is an essential sensor of ROS in pre‐adipocytes and controls their differentiation into mature adipocytes. NPGx belongs to