How to Make Lung (IMAGE) University of Pennsylvania School of Medicine Caption This shows normal and separate expression of Nkx2.1 (green) in lung endoderm and p63 (red) in esophagus endoderm (arrow) (Panel U). Activation of Wnt/beta-catenin results in reprogramming of esophagus endoderm to Nkx2.1 positive lung endoderm (panel V, arrow). Credit Edward Morrisey, PhD, University of Pennsylvania School of Medicine; Developmental Cell 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.