Furthermore, the possible development of cognitive impairment in patients with Long-COVID-19 who carry the APOE ε4 allele raises concerns about the later development of neurodegenerative diseases (mainly Alzheimer’s), given the known role of such an allele as a risk factor for sporadic Alzheimer’s, corroborated by animal models that show its role in inducing cerebral amyloidogenesis. The gene discussed is APOE; the disease is neurodegenerative disease.