That's all, folks? Just a few months into a clinical trial, researchers at the University of Pittsburgh have made "swift progress" using pig cells to regrow sizable chunks of missing human flesh. The first soldier to enroll in the trial lost 70 percent of his right quadricep in an attack — but now the missing flesh is back. "What would have been an amputation is now somebody with a limb that works," says Dr. Stephen Badylak. The Pentagon is pouring $250 million into regenerative medicine research, and Badylak's pig-protein procedure could become standard practice after the trial wraps in two years. Here's what you should know:

Pig cells help humans regrow body parts?
Badylak's technique uses something called an "extracellular matrix" containing "growth factor proteins from pig bladders," says Katie Drummond at Wired. Surgeons implant that mixture in damaged areas. It then attracts the body's regenerative stem cells and stimulates "the process of tissue and growth repair" — even on bones and nerve endings. Basically, we put a porcine "homing device" inside the body that "recruits (human) stem cells on its own," Badylak tells MSNBC. "It’s a shortcut."

And this works?
It does. Before the clinical trial began, 25-year-old Marine Cpl. Isaias Hernandez lost more than a quarter of his right thigh when a mortar exploded, causing shrapnel to slice violently through his legs. In 2008, he volunteered to be the first human test subject. "They cut a little slit into my thigh where they were going to put the material," Hernandez said. "It was like blood in an envelope." After months of regenerative therapy to train his new muscles, Hernandez can play sports and is trying to get "fit enough to re-join the Marines." 

What's next?
After successfully operating on four soldiers, the research team is training surgeons from around the country. For civilians, this treatment could even be applied to victims of car accidents, or be used to help people who lost limbs to diseases like cancer and diabetes. The prospects are "tantalizing," says Drummond.

Esquire, MSNBC, Wired