Frank Giordano's patients need new blood vessels: some have blocked arteries around their hearts, and others have poor circulation in their limbs. In a few cases, the Yale University cardiologist and molecular biologist has coaxed new vessels to grow using conventional gene therapy, injecting patients with genes that encode a natural protein called vascular endothelial growth factor. But he's most excited about a new treatment that, instead of relying on imported genes, stimulates the patients' own genes to work harder.

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