Alan R. Tall MB, BS is the Tilden-Weger-Bieler Professor of Medicine and head of the Division of Molecular Medicine in the Department of Medicine of Columbia University. Dr. Tall is internationally recognized for his work on plasma lipoproteins and atherosclerosis, especially regarding the regulation and metabolism of plasma high density lipoproteins (HDL). Dr. Tall discovered mutations in the cholesteryl ester transfer protein (CETP) gene that are associated with dramatically increased HDL levels and reduced LDL levels, establishing the role of CETP in the regulation of lipoproteins and identifying CETP as a potential therapeutic target. Dr. Tall has done research on the ATP binding cassette transporters ABCA1 and ABCG1 that promote cholesterol efflux from macrophage foam cells to apoA-1 and HDL particles, respectively. This work has also identified a key role of cholesterol efflux pathways in regulating the proliferation of hematopoietic stem and progenitor cells and thus the production of inflammatory cells and platelets. Recently the Tall laboratory has focused efforts on understanding the mechanisms underlying the association of human GWAS variants with plasma lipoproteins and coronary heart disease. This has led to an elucidation of the role of a scaffolding protein TTC39B in the ubiquitination and turnover of LXR, with impact on HDL levels, steato-hepatitis and atherosclerosis. Dr. Tall is a member of the Association of American Physicians and has served on the Board of Scientific Councilors of the National Heart, Lung and Blood Institute, the Research Committee and the ATVB Council of the American Heart Association. Dr Tall is an Associate Editor of Circulation Research and has been an Associate Editor and Editorial Board member of the Journal of Clinical Investigation and the ATVB journal. In recognition of his work, Dr Tall was the recipient of the Irvine Page Award, the Robert I. Levy Lectureship and the Distinguished Scientist Award of the American Heart Association.