Scientists discovered how to soften hair follicle stem cells to enable them to grow hair again. These cells stiffen with age and produce less hair. In a study in mice, the investigators report that they can soften the stem cells by boosting the production of a tiny RNA, miR-205, that relaxes the hardness of the cells. When scientists genetically manipulated the stem cells to produce more miR-205, it promoted hair growth in young and old mice.