AKT1 and Alzheimer disease: As a protein kinase, GSK3 can phosphorylate almost all downstream proteins with the S/T-X-X-X-S/T(P) motif, and is also dynamically regulated by multiple kinases including AKT, PKA, and PKC.106 Studies have confirmed that excessive activity of GSK3 is strongly correlated with neurodegenerative diseases such as AD, as described in detail below.