Researchers at the University of Pennsylvania School of Medicine, in Philadelphia, have discovered stem cells in the esophagus of mice that are able to grow into tissue-like structures and form parts of an esophagus lining when placed into immune-deficient mice.1 “The immediate implication is that we’ll have a better understanding of the role of these stem cells in normal biology, as well as in regenerative and cancer biology,” stated senior author Anil Rustgi, MD, professor of medicine and genetics and chief of gastroenterology at Penn. “Down the road we will develop a panel of markers that will define these stem...