Dr. Kelley’s research centers on the role of oxidative stress in vasculature inflammation with a primary focus on the modulation of endothelial homeostasis by xanthine oxidase (XO)-derived ROS. Such ROS production, when it occurs in the vascular compartment, can impact vessel function by modulation of redox-dependent cell signaling reactions or by the reduction of •NO bioavailability due to its direct reaction with superoxide. An expanding number of animal models and clinical studies affirm a key role for XO in tissue pathology where inhibition of XO activity attenuates symptoms of vascular disease. However, recently reported studies demonstrate under severe hypoxia, XO may function as a nitrite reductase and thus assume a protective role by serving as a source of vasoactive nitric oxide (NO). Therefore, in order to develop novel treatment strategies, Dr. Kelley’s efforts are globally targeted to develop a more comprehensive understanding of XO-derived ROS/RNS in vascular inflammatory processes.