In addition, it is a potent endogenous inhibitor of tumor suppressor serine-threonine phosphatase PP2A [16,17], whereby SET impairs the activity of PP2A toward its targets, including several kinases which mediate cancer cells’ survival [12,18,19] and the protein tau, which is key in the development of AD and other tauopathies [20]. The gene discussed is PTPA; the disease is cancer.