Cover: Millions of patients in the US each year present with wounds that fail to heal in a timely manner. Diabetic patients are particularly likely to be affected. Recent studies have elucidated changes in reactive oxygen species and the presence of bacterial biofilms as contributing factors to chronic wounds based on studies in human patients and mouse models of healing. For details see Nouvong A, Ambrus AM, Zhang ER, Hultman L, Coller HA. Reactive oxygen species and bacterial biofilms in diabetic wound healing. Physiol Genomics 48: 889–896, 2016.