However, another research observes the upregulation of claudin‐5 and claudin‐3 in iPSCs‐derived BMEC from AD patients (PSEN1), although deceased TEER value and decreased level of VE‐cadherin both reflect the decreased endothelial integrity, while no significant difference in the expression of ZO‐1 and occludin. The gene discussed is OCLN; the disease is Alzheimer disease.