CCKBR and Alzheimer disease: Among them, CCKBR, EGR3, FOSL2, HOMER1, KCNF1, NPTX1 and VEGFA constitute a network related to cardiovascular system development and function, organismal development, and cell signalling (Fig. 3b), and CCKBR, EGR3, HOMER1 and KCNF1 genes have been previously reported to be downregulated in human AD hippocampus18.