APOE genotype plays a crucial role in determining the risk and severity of cerebral amyloid angiopathy (CAA), a common form of cerebral SVD characterized by accumulation of amyloid-β (Aβ) in the CNS leptomeningeal medium and small arteries (Rannikmae et al., 2013). The gene discussed is APOE; the disease is cerebral amyloid angiopathy.