In early 2009 Mike Jones bought a newspaper at a convenience store in Louisville, Ky., and read about a local doctor who wanted to try something unprecedented: healing an ailing heart by harvesting and multiplying its native stem cells—immature cells with regenerative powers. Jones, then 65, had congestive heart failure: his heart was no longer pumping blood efficiently. He contacted the doctor, Roberto Bolli of the University of Louisville, and in July of that year Jones became the first person in the world to receive an infusion of his own cardiac stem cells.