There are positive K14-K5 double immunohistochemistry staining cells appeared in the cultured ESC 24 hours after SP was added into culture media.

• 在体外培养表皮干细胞中给于SP刺激后24小时就发现培养的表皮干细胞中出现了K14和K5双标染色阳性细胞（短暂扩充细胞），提示表皮干细胞分化进入短暂扩充细胞。