Within every blood sample lies a hidden minority — rare cells that may quietly determine whether a patient recovers or declines, yet remain invisible to the tools we rely on most. At the University of Virginia, engineer Nathan Swami has received a four-year, $1.1 million NIH grant to build the instruments and intelligence needed to find and interrogate these elusive cells. His work sits at the intersection of microengineering, artificial intelligence, and medicine, pursuing a question as old as diagnosis itself: why do some patients respond to treatment while others do not? The answer, he beli