MAPT and argyrophilic grain disease: AGD is distinguished by the presence of argyrophilic granules, from which it derives its name, as well as comma-shaped dendritic protrusions predominantly consisting of phosphorylated 4R Tau, which are crucially involved in the main neuropathologic features, the so-called “coiled bodies”, oligodendroglial TAU inclusions that go along with “ballooned” neurons [87, 94].