PPP1R1B and neurodegenerative disease: Depending on its cofactor, CDK5 in the brain phosphorylates targets involved in neurodegenerative diseases (e.g. Tau, MAP1B), neuronal migration (e.g. DCX), and synaptic signaling (e.g. Cav2.2, Dynamin1, NR2A, DARPP-32) (Kawauchi, 2014).