MAPT and tauopathy: For example, the phosphorylated form of tau is known to associate with tubulin to stabilize axonal microtubules and promote tubulin polymerization into microtubules, and abnormal phosphorylation of tau results in the destabilization of axonal microtubules, leading to the development of Alzheimer's disease and many other neurodegenerative diseases collectively called tauopathies [5].