APOC1 and Alzheimer disease: Another AD risk gene, APOC1, and its 8 neighbor genes (such as ADORA2A, CDH2, and SLC28A2) were enriched in functions related to negative regulation of hydrolase activity (PBH = 0.01), regulation of synaptic transmission, glutamatergic (PBH = 0.01), negative regulation of phosphatidylcholine catabolic process (PBH = 0.01), and so on (Fig. 6E right plot).