Докторъ [Public domain] via Wikimedia CommonsAndrogenetic alopecia (AGA), more commonly known as male pattern baldness, occurs in almost 80% of men during their lifetimes. Despite this high prevalence, little is known about its causes or potential treatments. George Cotsarelis (University of Pennsylvania, Philadelphia) and colleagues sought to identify genetic factors involved in the condition by comparing gene expression levels in balding and non-balding scalp tissue from men with AGA.