Epithelial cells are a type of cell that line the surfaces of various organs and structures within the body. These cells form a protective barrier between the internal and external environments and are involved in the secretion and absorption of substances. Research on epithelial cells often focuses on their function in different organs, their role in diseases such as cancer and inflammation, and potential therapeutic strategies to target these cells for various medical conditions. Studies on epithelial cells have also provided insights into cell communication, differentiation, and tissue repair processes.