Nicholas Arpaia (IMAGE) Columbia University Irving Medical Center Caption Nicholas Arpaia, PhD, assistant professor of microbiology and immunology at Columbia’s Vagelos College of Physicians and Surgeons Credit Columbia University Vagelos College of Physicians and Surgeons Usage Restrictions Credit must be given to the creator. Adaptations must be shared under the same terms. License CC BY-SA 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.