A trifling paper cut is a site of frenzied activity. Within it, a squad of epidermal stem cells briskly regenerate to patch up the wound. A closer inspection of this war-torn swath of epidermis will reveal that while some of the stem cells are native to the area, others are newcomers—former hair-producing stem cells, that—upon sensing nearby injury—migrated from the hair follicle to the wound bed, where they transformed to resemble indigenous epidermal stem cells … read more