Lab-grown penises could be the next big thing.

Researchers at Wake Forest Institute for Regenerative Medicine in North Carolina say they are only five years away from testing bioengineered penises on humans, The Guardian reported.

The new technology would benefit men who have suffered injuries in the area or undergone surgery for cancer, as well as those born with congenital abnormalities.

The scientists hope to get the penises approved by the US Food and Drug Administration within five years, so they can start testing them on human subjects.

So far, they’ve only been successful with rabbits.

“The rabbit studies were very encouraging,” Professor Anthony Atala told The Guardian, “but to get approval for humans we need all the safety and quality assurance data, we need to show that the materials aren’t toxic, and we have to spell out the manufacturing process, step by step.”

Since transplanted organs are often rejected by the body, these penises would be constructed with a combination of the patient’s cells – which would be grown in culture for four to six weeks — and a donor’s penis.

The donor’s organ would be washed clean of all previous cells with a mild detergent of enzymes — and then the patient’s cultured cells would be added to it.

The US Armed Forces Institute of Regenerative Medicine is one of the sources of funding for Atala’s research and envisions the engineered organs as being a benefit to soldiers who have suffered battlefield injuries.

“Our target is to get the organs into patients with injuries or congenital abnormalities,” Atala said.