Physiological Reviews Associate Editor Prof. Giovanni Mann speaks with Prof. Rafael Radi about his review article “The superoxide radical switch in the biology of nitric oxide and peroxynitrite,” about the life of a scientist, and about advice for early-career researchers. Prof. Radi is Professor, Chair, and Director of the Centro de Investigaciones Biomédicas (CEINBIO) at the Universidad de la República in Montevideo, Uruguay. Prof. Radi has made significant contributions to our understanding of the mechanisms of nitric oxide-dependent toxicity through its interaction with superoxide anions and the formation of peroxynitrite. He has characterized the biological chemistry of peroxynitrite, its effects on mitochondrial dysfunction and apoptosis, and its role in pathology. Introduction of Prof. Radi [0:45] Author's background [2:40] Advice to early-career investigators seeking to take on a career in research [10:07] Discussion of collaboration between professional organizations that facilitates sharing of research among early-career researchers from different countries [13:57] Insight into the sources of superoxide, and which in particular Prof. Radi believes contributes primarily to the role of superoxide acting as a ‘radical switch’ [16:37] The importance of physiologically relevant oxygen levels in the interplay of nitric oxide, oxygen, and peroxynitrite during experiments [20:54] From a translational perspective, can this area of inquiry make any contributions to benefit patients? [25:13] Will basic and clinical scientists be able to target specific activators or inhibitors of nitric oxide synthase(s) or nitric oxide donors to individual organs or tissues? [29:07] Formation of peroxynitrite under lower oxygen levels [31:28] Advice for young people interested in pursuing basic science and/or medicine as a career [35:33] Subscribe to the podcast on Apple Podcasts, Google Podcasts, Spotify, and Amazon Music to receive immediate notification when new episodes are available. Browse recent articles on our website. Be sure to let your colleagues know about the podcast, and please rate and review it wherever you listen to it. Follow the journal on Twitter and Facebook. Listen to other podcasts produced by the American Physiological Society.