By contrast, in pathological conditions, following mechanisms still not well characterized, Fyn mediates Plexin-A2 hyperphosphorylation thus activating downstream signaling that have been associated with several neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease, multiple sclerosis and Amyotrophic lateral sclerosis [123,124,125,126]. Here, FYN is linked to neurodegenerative disease.