The role of claudin 3 in contributing to the BBB integrity however is controversial: Whereas some authors have shown an impaired BBB in claudin 3 knockout (KO) mice exhibiting an experimental autoimmune encephalomyelitis [14], Dias and coworkers found that absence of claudin 3 in KO mice did not alter BBB function during neuroinflammation in mice [15]. This evidence concerns the gene CLDN3 and experimental autoimmune encephalomyelitis.