Mainly associated with abnormalities that result in neurodegenerative diseases. Tau proteins stabilize microtubules, and thus shift the reaction kinetics in favor of addition of new subunits, accelerating microtubule growth. Tau has the additional function of facilitating bundling of microtubules within the nerve cell. The function of tau has been linked to the neurological condition Alzheimers disease. In the nervous tissue of Alzheimers patients, tau forms abnormal aggregates. This aggregated tau is often severely modified, most commonly through hyperphosphorylation. As described above, phosphorylation of MAPs causes them to detach from microtubules. Thus, the hyperphosphorylation of tau leads to massive detachment, which in turn greatly reduces the stability of microtubules in nerve cells.[9] This increase in microtubule instability may be one of the main causes of the symptoms of Alzheimer's disease.