Hair restoration includes the medical and surgical treatment of various forms of hair loss. The most common cause of hair loss is androgenetic alopecia (AGA), also known as male pattern baldness or female pattern baldness. The most common hair restoration surgery technique is follicular unit transplantation (FUT). In FUT, follicular units are extracted from the back of the head, where hair tends to be more permanent, and planted into areas where hair is thinning or absent. Research now suggests that stem cell therapies can be used to restore hair follicles.