As long ago as the mid-19th century, scientists suspected that the cells of living things must contain specific channels that allow water to pass in and out of the cells, a process essential to all organisms, but it was not until the late 1980s that Dr. Peter Agre succeeded in isolating a membrane protein that proved to be the long-sought-after water channel. A graduate of Johns Hopkins University School of Medicine, Dr. Agre joined the Hopkins faculty in 1984, gradually shifting from clinical work to laboratory research. In 1988, Agre and his colleagues were searching for proteins that are part of the Rh-factor when they happened across an abundant and much smaller protein of unknown function. The mysterious protein proved to be the elusive cellular regulator of water transport, the "water pore," or aquaporin. Since a 1992 paper in Science, co-authored by Agre, documented the first discovery of an aquaporin, hundreds more have been found in animals, plants, bacteria and other forms of life. Researchers have linked aquaporin malfunction to diseases of the kidneys, heart, muscles and nervous system. Agre, now Professor of Biological Chemistry at Hopkins, was awarded the 2003 Nobel Prize in Chemistry for his discovery. "In the future," Agre says, "we will be able to capitalize on our understanding of aquaporins to benefit medicine, biotechnology and even agriculture."