CLDN5 and cerebral cavernous malformation: The expression of Claudin-5 and VE-cadherin in the lesions with CCM gene mutations was significantly lower than that in the control samples (p < 0.05; t-test), while no difference was found in VE-cadherin expression in the MAP3K3-mutant samples compared with that in the control samples (p =0.2069; t-test) (Figures 4B,C).