Do hair roots grow back?

Humans are born with the total number of hair roots, or hair follicles, they will have throughout their lifetime. Although hair follicles do not grow back, according to ABC News, an accidental discovery made in May 2014 in an experiment involving lab mice may change that someday.

University of Pennsylvania scientists working with wounded lab mice discovered by chance that mice that first had their skin scraped developed new hair follicles as they healed. ABC News reports that it is not known if this discovery is applicable to humans or if scientists will find a way to create hair growth in humans without actually harming them.