Claudins are a family of 27 proteins that have an important role in the formation of tight junc-tions. They also have an important function in ions exchange, cell mobility, and in in the epitheli-al-to-mesenchymal transition, the latter being very important in cancer invasion and metastasis.
Therapeutic targeting of claudins has been investigated to improve cancer outcomes. Recent evi-dence shows improved outcomes when combining monoclonal antibodies against Claudin 18.2 with chemotherapy for patients with gastroesophageal junction cancer. Currently Chimeric anti-gen receptor T-cells targeting Claudin 18 are under investigation.