Cerebral amyloid angiopathy (CAA), which involves cerebrovascular deposition of β-amyloid (Aβ) proteins, is the major vascular aetiology underlying spontaneous lobar intracerebral haemorrhage (ICH) in elderly individuals.1 Aβ plaques in the parenchyma and neurofibrillary tangles comprised of hyperphosphorylated tau proteins are the histopathological hallmarks of Alzheimer’s disease. The gene discussed is MAPT; the disease is Alzheimer disease.