Swedish researchers have found in studies with mice that actively growing stem cells play a key role in keeping hair follicles healthy. The group found that active stem cells had a specific protein on their surface, called Lgr5. These stem cells were long-lived and showed rapid growth. In the mouse studies, just a few of these cells were able to build an entire hair follicle. While it will still be some time before the results can be applied to humans, the study provides some hope for the follicularly challenged who miss their coiffure. The published study also notes that the same protein has been identified on stem cells in the intestine. So, it may take real guts (transplanted) to grow hair...