Androgenetic alopecia (AGA) is a frequent form of hair loss in both men and women. However, it is more common in men, in whom it is also known as male-pattern baldness.

Through the analysis of bald and non-bald scalp samples from men with AGA, a team of researchers, led by George Cotsarelis, at the University of Pennsylvania School of Medicine, Philadelphia, has gained new insight into the underlying causes of AGA. Specifically, the data indicate that a defect in the conversion of hair follicle stem cells to progenitor cells has an important role in AGA.

The authors therefore suggest that further studies defining the signals responsible for the transition of stem cells to progenitor cells could provide new therapeutic targets for the treatment of AGA.