机体所有能自我更新的组织中都有干细胞的存在。干细胞是成熟机体中具有多潜能的细胞 ,能自我维持 ,细胞周期长 ,能进行不对称的细胞分裂 ,缺乏分化特性 ,形态和生化处于原始幼稚阶段 ,是细胞自我更新和增殖的源泉。角膜上皮也存在干细胞。目前对角膜上皮干细胞的研究日益深入 There are stem cells in all the tissues in the body that are self-renewing. Stem cells are pluripotent cells in mature organism. They are self-sustaining, have a long cell cycle, are capable of asymmetric cell division and lack of differentiation. Morphology and biochemistry are in primitive naive stages and are the source of cell self-renewal and proliferation. There are also stem cells in the corneal epithelium. At present, the research on corneal epithelial stem cells is more and more in-depth