Increased FYN expression and phosphorylation, a marker of FYN activation, has been identified in AD and PD patient brain tissue (Guglietti et al., 2024; Low et al., 2021; Panicker et al., 2019), and FYN activation has been reported to correlate with microglia activation (Panicker et al., 2019). This evidence concerns the gene FYN and Alzheimer disease.