Numerous studies, backed by meta-analyses, have revealed that APOE4 is also a risk factor for other diseases [20], including cerebral amyloid angiopathy (CAA) [21], dementia with Lewy bodies (DLB) [22], tauopathy [23], cerebrovascular disease [24], multiple sclerosis [25, 26], and vascular dementia [24, 27], as well as being related to poor outcome following head injury [28, 29]. The gene discussed is APOE; the disease is vascular dementia.