Dr Croitoru is a Professor of Medicine and Immunology at the University of Toronto (U of T) and Clinician-Scientist at Mt Sinai Hospital, Lunenfeld Tanenbaum Research Institute. After clinical training in gastroenterology at McGill, he did a research fellowship at McMaster University in mucosal immunology. He then established a research program on the role of T cells in mucosal inflammation and host- bacterial interactions. In 2008, he joined Mt Sinai Hospital IBD Center at the University of Toronto where his current research focuses on host-microbe interactions and IBD pathogenesis.  He leads the CCC GEM project, a prospective cohort study of healthy individuals at risk of developing Crohn's disease (CD). The project searches to identify the genetic, environmental and microbial determinants that trigger CD. He currently holds a Canada Research Chair in Inflammatory Bowel Diseases and recieved the Department of Medicine Eaton Scholar Award in Research (Basic Science) in 2023.