The Pennsylvania Republican has Hodgkin's disease, a cancer of the lymph system, and is being treated with chemotherapy. He and two colleagues introduced a bill Thursday that would allow for what is often referred to as therapeutic cloning.

''I've got a new hairdo, which you can all observe, and that is indicative of a problem which may well be helped by stem cell research if it were to go forward,'' said Specter, referring to the loss of most of his hair.

Specter was joined at a news conference by Sens. Orrin Hatch, R-Utah, and Dianne Feinstein, D-Calif.

The three said their bill would make reproductive cloning, to produce a baby, a crime punishable by up to 10 years.

But they do want to allow for ''therapeutic cloning'' for the purpose of obtaining stem cells to be used in treating disease.