Rescue effects of CCM1 and CCM2 overexpression on Ngbr deficiency–induced endothelial defects and cerebrovascular lesions further demonstrated that CCM1 and CCM2 downregulation contributes to the pathogenesis of CCM-related vascular lesions in the brain of NgbrECKO mice. The gene discussed is KRIT1; the disease is cerebral cavernous malformation.