A man known for his days as Superman made a plea for Congressional support for cloning cells Saturday night at Stephens Auditorium.

Christopher Reeve — the actor who had the title role in many “Superman” movies — spoke to a crowd of more than 200 with U.S. Senator Tom Harkin.

After Harkin and Reeve arrived on stage, the audience viewed a video endorsement for Harkin from another famous actor — Michael J. Fox.

Fox, who suffers from Parkinson’s disease, thanked Harkin for his work in supporting bills to help fund medical research.

Reeve said he supports Harkin’s legislation allowing the cloning of cells for medical research while outlawing human reproductive cloning.

Reeve argued in support of the allowance and regulation of cloning for medical research and the prohibition of cloning humans.

“Many feel this is a slippery slope, and that this research could not be regulated,” Reeve said.

“There is a tremendous difference between reproductive cloning and therapeutic cloning.”

Reeve stressed the benefits of stem-cell research, a possibility he said Harkin and several other politicians have already grasped.

“[Stem-cell research] is going to give over 100 million Americans with incurable diseases and 54 million Americans with disabilities, for the first time, real hope,” he said.

Reeve said political leaders must establish strict penalties for individuals or corporations who attempt human cloning.

“The government must step in now,” he said. “Otherwise, somebody is going to try to [clone humans]. That would be very bad for the country.”

Harkin said his opponent, Greg Ganske, has asserted Harkin supports human cloning.

“I am totally opposed to human reproductive cloning,” Harkin said. “What we are talking about is promising new research possibilities.”