KRT15 and Hand-foot syndrome: Since some K15 (Keratin 15, a bona fide marker of eHFSCs) positive cells also co-express vimentin [43], this suggests that some eHFSCs in FFA HFs undergo EMT [43] and contribute to the prominent fibrosis observed in FFA, which in addition to eHFSC apoptosis observed in FFA, functions to deplete the bulge stem cell niche even further.