KRT19 and Alzheimer disease: Then phosphorylated Tau, including pTau40 and pK19, were prepared by phosphorylating purified Tau40 and K19 using kinase MARK2 which was previously identified to be important in mediating pTau pathology in AD (Ando et al., 2016; Drewes, 2004; Gu et al., 2013).