角蛋白(keratin)是一组分子量为40,000～70,000的不溶于水的细胞结构蛋白,在胞浆中形成直径为10nm左右的中间丝(intermediate filament),与微管和微丝一起构成细胞骨架系统。近年研究证明,细胞骨架蛋白仅见于上皮分化细胞,并作为上皮细胞来源的一种标志用于上皮性肿瘤的诊断、鉴别诊断、分型和上皮细胞的功能分化等研究。 Keratin is a group of water-insoluble cell structural proteins with a molecular weight of 40,000 to 70,000. It forms intermediate filaments with a diameter of about 10 nm in the cytoplasm and forms a cytoskeletal system together with microtubules and microfilaments. . Recent studies have demonstrated that cytoskeletal proteins are only found in epithelial-differentiated cells and serve as a marker of epithelial cell origin for the diagnosis, differential diagnosis, classification and functional differentiation of epithelial cells.