NOS2 and Dowling-Degos disease 1: Additionally, respective increases were observed in inducible nitric oxide synthase (iNOS) deficiency, COX‐2, IL‐1β, IL‐6, MMP‐13, ADAMTS5, and TNF‐α when compared to controls, indicating an inflammatory cascade potentiating the generation of potential reactive oxygen species (ROS) and ultimately cell death in young patients, leading to DDD.