Researchers claim to have discovered cause of male pattern baldness

There's hope out there for all men losing hair up top.

Researchers say they've found a biological clue to male pattern baldness.

They say prostaglandin, called PGD2, is more plentiful in the bald areas of the head. PGD2 helps with the contraction of smooth muscles.

Now doctors think if they can find a way to block PGD2 from binding to hair follicles, they could stop baldness.