Claudin-1 is an integral membrane protein of about 23 kDa, mapada on chromosome 3, whose function is cell adhesion. Is involved in cell growth and maintenance and is present in the tight junctions between cells, structures whose main functions emphasizes maintaining the differentiation state of epithelial cells. Recently it was reported that claudin may be, if not cause, itself a marker for the progression of certain carcinomas and metastases. (more...)