The disclosure provides isolated hair follicle stem cells (hfSC) having inactivated BMP signaling, which are discovered to express keratin 15. Also provided are hfSC that have constitutively activated BMP signaling and methods of using such hfSC for screening candidate agents suitable for inhibiting BMP signaling in hfSC and promoting hair growth. Further provided are methods of activating hfSC and promoting hair growth from hfSC.
