What are the potential therapeutic benefits of Cannabis to ameliorate physical and psychological illnesses? Because of the constraints on conducting medical research on Cannabis and related products, much available information is empirical and has not been subjected to the rigors of the scientific method. What are the outstanding questions, and how might they be most usefully addressed through research and clinical practice? Donald I. Abrams, MD is the chief of the Hematology-Oncology Division at Zuckerberg San Francisco General Hospital and a Professor of Clinical Medicine at the University of California San Francisco. He is a graduate of Brown University and the Stanford University School of Medicine. He did his residency in internal medicine at Kaiser San Francisco and his fellowship at the University of California San Francisco. He was an early pioneer in HIV/AIDS medicine when he was challenged to conduct a clinical trial of cannabis for the AIDS wasting syndrome. He received his first NIH grant to study inhaled cannabis in 1997 and has also been funded by the University of California Center for Medicinal Cannabis Research to conduct subsequent clinical trials. He has studied the effects of cannabis in peripheral neuropathy, in association with sustained release opioids and in patients with sickle cell disease. He was a member of the committee that wrote the 2017 publication from the National Academies of Sciences, Engineering and Medicine on The Health Effect of Cannabis and Cannabinoids.