In the next few years, researchers at the Wake Forest Institute for Regenerative Medicine hope to transplant lab-grown penises into people who need them due to congenital abnormalities, disease, or traumatic injury.

The penises are grown from the patient's own cells on a 3D collagen scaffold made from a donor penis. Studies on rabbits "were very encouraging," says tissue engineering pioneer Anthony Atala, director of the Institute. From The Guardian: