NDUFB4 and Alzheimer disease: A total of 12 genes related to the AD pathway were highly expressed in the endothelial cells and pericytes, which included APP, COX7A1, UQCRQ, ATP5PF, NDUFA8, NDUFB4, NDUFB6, COX6C, COX5B, BAD, COX7A2, and NDUFC1 (Figure 4B).