FYN and Alzheimer disease: Under oxidative stress conditions such AD or PD, Nrf2 modulates its activity through Fyn protein phosphorylation induced by GSK-3β [43,44] Phosphorylated Fyn protein translocates and accumulates in the nucleus and phosphorylates Nrf2, leading to its nuclear export, ubiquitination, and degradation [45,46] (Figure 2).