NDUFA2 and Alzheimer disease: In early HEV gt3 infection, genes associated with mitochondrial oxidative phosphorylation, Huntington’s disease, Alzheimer’s disease, and Parkinson’s disease pathways were upregulated (Table 2), where genes in respiratory chain complex I (NDUFA1, NDUFA2, and NDUFS7), complex II (SDHC and SHHD), complex III (UQCRFS1), and complex V (ATP5D and COX5b) of oxidative phosphorylation were upregulated (S1 Table).