Hair follicles contain a pool of undifferentiated melanocyte stem cells ( MSCs), which are sources of differentiated melanocytes, and functional melanocytes exhist in the hair bulb.

• 毛囊内包含存在于外根鞘的、可作为黑素细胞“贮库”的未分化的黑素母细胞, 以及毛球部有活性的黑素细胞。