Since PP2A activity has been shown to be decreased in the brains of patients with AD [58], in vivo use of OA has also been revealed as an excellent way to understand diseases accompanied by protein hyperphosphorylation and cognitive deficits [38], as it is believed that protein hyperphosphorylation is due to inhibition of phosphatases in vivo and induces neuronal stress and subsequent neurodegeneration. Here, PTPA is linked to Alzheimer disease.