Andrew R. Marks, M.D. is chair and professor of physiology and cellular biophysics at Columbia University. He discovered that ‘leaky’ intracellular calcium-release channels (ryanodine receptors, or RyR) contribute to heart failure, cardiac arrhythmias, impaired exercise capacity, post-traumatic stress disorder and Alzheimer’s disease. He developed a new class of small molecules (Rycals) targeting leaky RyR. Rycals are in clinical trials for heart failure, cardiac arrhythmias, and Duchenne muscular dystrophy.