Dr. Cohen received his M.D. from the University of Pennsylvania School of Medicine. He completed internal medicine residency training at the Massachusetts General Hospital and then obtained fellowship training in adult hematology and medical oncology at the Dana-Farber/Brigham and Women’s and Massachusetts General Hospital combined fellowship program. Following fellowship, he became an Instructor at the MGH where his research focused on the role of angiogenic progenitor cells in tumor vascular biology. He was then recruited to the University of Chicago in 2007 as an Assistant Professor of Medicine. He is currently an Associate Professor of Medicine at the University of Chicago. He serves as Program Director of the Adult Hematology/Oncology Fellowship Program and is Program Leader of Classical Hematology. Clinically he cares for patients with HHT as well as disorders of thrombosis and hemostasis. He is Director of the University of Chicago HHT Center of Excellence.