BDNF and Alzheimer disease: Intriguingly, although DE genes in both the FUS and HPC were enriched in the PI3K/AKT/GSK-3β pathway, which is likely activated by neurotrophins and plays critical roles in AD onset and progression [28, 29], 84% (21 of 25) of the DE genes associated with this pathway in the FUS were upregulated in AD patients compared to controls (Fig. 1c).