A veteran nearly lost it all to an IED blast in Afghanistan — a pioneering procedure changed everything. "Penis transplantation is a radical frontier of modern medicine: extremely rare, expensive, and difficult to perform. Replacing a major organ like a damaged liver is one thing: it contains just one type of tissue. But grafting a penis from a deceased donor onto a living recipient is a chaotic amalgamation that entails stitching millimetres-wide blood vessels and nerves with minuscule sutures." Andrew Zaleski, writing in MIT Technology Review, explores.