Hair follicles are self-renewing structures that cycle and reconstitute themselves throughout life because they contain keratinocyte stem cells. The interplay between keratinocytes and underlying mesenchyme are critical for hair follicle morphogenesis and cycling. Several key developmental pathways are involved in determining follicular keratinocyte fate as well as the differentiation into several distinct cellular layers of the follicle during the growth phase of hair. Studies indicate that follicular keratinocytes are distinct from epidermal keratinocytes in proliferative capacity and CD34 expression.HHFK from AcceGen Research Laboratories are isolated from human hair follicles. HHFK are cryopreserved on primary culture and delivered frozen. Each vial contains >5×10^5 cells in 1 ml volume. HHFK are characterized by immunofluorescent method with antibodies to cytokeratines. HHFK are negative for HIV-1, HBV, HCV, mycoplasma, bacteria, yeast and fungi. HHFK are guaranteed to further expand for 15 population doublings in the condition provided by AcceGen Research Laboratories.