Asthma Trigger (IMAGE) University of Pennsylvania School of Medicine Caption Increased neuropeptide Y expression in the epithelium of Foxp1/4 double knockout mouse lung tissue (arrowheads) compared to control mouse lung tissue. Ai = airway. Credit The lab of Edward E. Morrisey, PhD, Perelman School of Medicine, University of Pennsylvania, Journal of Clinical Investigation Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.