Barrier function refers to the protective role of biological barriers in the body that prevent the entry of harmful substances such as pathogens, toxins, and allergens. These barriers can include physical barriers like the skin and mucous membranes, as well as chemical and immunological barriers such as enzymes and antibodies. Research in barrier function focuses on understanding the mechanisms by which these barriers function, as well as how they can be compromised in various diseases and conditions. This can include studying the structure and function of the barrier tissues, as well as the role of specific molecules and signaling pathways in maintaining barrier integrity. Overall, research in barrier function is important for understanding and developing new therapies for a wide range of diseases and conditions, from skin disorders to autoimmune diseases to infections.