Limber Lungs (image) University of Pennsylvania School of Medicine Share Print E-Mail Caption Adult lung cells regenerating: Type 1 cells are green. Type 2 cells are red. New Type 2 derived from Type 1 cells are yellow. Nuclei are blue Credit Jon Epstein, MD & Rajan Jain, MD, Perelman School of Medicine at the University of Pennsylvania, and Christina Barkauskas & Brigid Hogan, Duke University Usage Restrictions None Share Print E-Mail 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.