CCM2 and cerebrocostomandibular syndrome: Although KRIT1, CCM2 and CCM3 are broadly expressed, the cell type most strongly linked to CCM lesions is the endothelial cell; indeed, endothelial-specific deletion of KRIT1, CCM2 or CCM3 in mice results in lesions in the brain neurovasculature, mimicking human CCMs [43,47,48].