RNF213 and Moyamoya disease: Rnf213 is the main susceptibility gene for moyamoya disease (MMD) [22, 30], a specific intracranial vascular disorder characterized by progressive, occlusive lesions of internal carotid arteries and branches in the circle of Willis, resembling a puff of smoke (upon contrast angiography) that is called “moyamoya” in Japanese [31–33].