We then examined changes in the expression levels of the candidate key genes associated with AD (MMP1, BHLHE40, NEAT1, ADORA3, and PPARG) in the combined dataset, and discovered that MMP1, BHLHE40, NEAT1, and ADORA3 were all overexpressed in the AD group compared with their levels in the control group (Figures 7A–C, E), whereas PPARG showed reduced expression in the AD group as opposed to the control group (Figure 7D). Here, MMP1 is linked to Alzheimer disease.