Thomas Smithgall, Ph.D. (IMAGE) University of Pittsburgh Caption Thomas Smithgall, Ph.D., the William S. McEllroy Professor and former chair of the University of Pittsburgh School of Medicine’s Department of Microbiology and Molecular Genetics Credit John R. Engen, Ph.D. Usage Restrictions Only for use in reporting on this study License Original 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.