MAPT and tauopathy: Besides the cellular kinases such as GSK3β that are activated by HSV-1 to phosphorylate Tau, HSV-1-encode kinases, i.e., serine/threonine-protein kinase UL13 and US3, can directly phosphorylate tau to its hyperphosphorylation form, further exacerbating tauopathy and neurodegeneration (Benetti and Roizman, 2004; Devanand, 2018).