One of the greatest mysteries in biology, until 1991, was how water moves across cell membranes. Today's episode focuses on the history of the discovery of aquaporins, or proteins that act as water channels in cell membranes. My guest is Peter Agre, recipient of the 2003 Nobel Prize in Chemistry for his discovery of aquaporins. Among many other honors and leadership roles across his career, Peter became a member of the U.S. National Academy of Sciences in 2000 and served as President of the American Association for the Advancement of Science from 2009-2010. He is the Bloomberg Distinguished Professor in Molecular Microbiology and Immunology and in the School of Medicine at Johns Hopkins Bloomberg School of Public Health. Peter is also the Director of the Johns Hopkins Malaria Research Institute.