In this session on work in progress in the NHLBI-sponsored severe asthma research program, there are four presentations planned to provide the learner with a cutting-edge, data-driven understanding of the clinical features of pediatric and adult severe asthma. Each presentation will cover the context, rationale and recent progress in addressing clinically relevant questions in severe asthma pathobiology, diagnosis and management, including baseline cross-sectional data on recruited healthy and asthmatic subjects, their response to systemic corticosteroids, risk factors for asthma exacerbations as well as advances in imaging for the detection of pathologic mucus and its association with clinical outcome.