On September 12, 2018, the 4th Annual New York City IBD Research Day was hosted by New York University Langone Health in the Farkas Auditorium. This yearly symposium is a collaborative effort of four institutions: The Jill Roberts Institute at Weill Cornell Medicine, The Immunology Institute of the Icahn School of Medicine at Mount Sinai, The Center for Basic and Translational Research on Disorders of the Digestive System at The Rockefeller University and The Skirball Institute and the Departments of Medicine and Surgery at New York University Langone Health. The big announcement this year was that Columbia University will join this group of institutions, hosting the 2019 NYC IBD Day. In honor of the late Lloyd F. Mayer, MD, there is a Mayer Prize given yearly. Dr. Sergio Lira presented the Mayer Prize to his friend and colleague, Dr. Dan Littman. Throughout the course of the day, the attendees listened to ten presenters, who had traveled from around the globe for this event, engaging in lively Q & A conversations afterwards. This year, Irina Leonardi, a Postdoctoral Associate from the Jill Roberts Institute, was invited to be a speaker in the highly-regarded program. She presented a seminar entitled, “Immune Recognition of the Intestinal Mycobiota.” Generous sponsorship from The Helmsley Charitable Trust, the NY Crohn’s Foundation, the Kenneth Rainin Foundation, Cure for IBD, Pfizer, Boehringer Ingelheim, Regeneron, and Janssen made the enriching day possible.