MAPT and Alzheimer disease: OKA-induced inhibition of these protein phosphatases, in particular PP2A, has previously been shown to cause tau hyperphosphorylation and NFT formation, as well as other hallmarks of AD pathology both in vitro and in vivo (Hensley et al., 2010a; Zhang and Simpkins, 2010; Kamat et al., 2012a,b, 2013, 2014; Kamat and Nath, 2015).