Researchers at the Univ. of Pennsylvania say they have identified the scalp chemical that stops hair from growing, and believe it may finally—finally!—lead to the elusive cure for male pattern baldness.

The scientists found that a protein called PDG2 was three times as prevalent on the scalps of balding men. (PDG2-blocking drugs are already being tested by researchers working on alternative treatments for asthma, so they're hopeful testing for baldness can be expedited.)

The news was met with joy in England, where an estimated 7.4 million men are bald or balding.

"Excitingly," the Daily Mail reported, "drugs that block the protein have already been developed for other purposes, meaning a hair restoring lotion or potion could be on the market in under five years."

"The nice thing about dermatology and hair loss in general is that you can take compounds that maybe are being used as a pill and put them in a topical formulation," Dr. George Cotsarelis, who authored a study on the findings, told the paper. "When you apply this to the scalp, you would allow hair to grow."

But the George Costanzas of the world should note: In 2008, Cotsarelis told the "Today" show that, after a similar lab discovery, a marketable cure was "possible within a few years."

Until then, men will undoubtedly continue to resort to expensive treatments for hair loss and regrowth. According to In Touch, actor Tom Cruise wears a "helmet-like device"—the $699 "Hands Free Hair Rejuvenator"—for 25 minutes a day to stave off hair loss.

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