Humans aren't capable of regenerating lost limbs, but our bodies can heal from many wounds. Whenever we scratch or cut our skin, for example, skin stem cells move in to regrow the epidermis and repair ...

Hair follicle stem cells (green) mobilize and expand (white) to help repair the skin’s barrier by differentiating into epidermal lineages (red). When a child falls off her bike and scrapes her knee, ...