Claudin-1 (CLDN1)

Claudins function as important elements of the tight junction complexes that regulate the permeability of epithelia. While some claudin family members play essential roles in the formation of impermeable barriers, others mediate the permeability to ions and small molecules.

Many times, several claudin family members are coexpressed and socialize with each other, and this determines the overall permeability. CLDN1 is required to protect against the paracellular diffusion of small molecules through tight junctions in the epidermis and is required for the normal barrier function of the epidermis.