The presence of ApoE4 protein has been associated with negative ramifications in regards to traumatic brain injury, stroke, frontotemporal dementia, Down syndrome, Parkinson’s disease, and Lewy body disease [1, 9], in addition to having been shown to increase the risk of Alzhiemer’s disease (AD) three–fourfold in heterozygotes and about 9–15 fold in ApoE4 homozygotes compared to non-carriers of the ApoE4 protein [2, 10, 11]. The gene discussed is APOE; the disease is Parkinson disease.