The involved KEGG pathways were mainly the Alzheimer disease (hsa05010), serotonergic synapse (hsa04726), the calcium signaling pathway (hsa04020), the PI3K-Akt signaling pathway (hsa04151), dopaminergic synapse (hsa04728), the neurotrophin signaling pathway (hsa04722), the notch signaling pathway (hsa04330), and cholinergic synapse (hsa04725) (Figure 6B). Here, BDNF is linked to Alzheimer disease.