MAPT and Alzheimer disease: Furthermore, by using a combination of ThT assay, Transmission Electron Microscopy (TEM) staining, analytical High-Performance Liquid Chromatography (HPLC) and Mass Spectrometry (MS), Eberle and colleagues have recently reported that tau is proteolytically cleaved in vitro by the viral SARS-CoV-2 3CL protease with a consequent release of the 25kDa fragment, triggering the formation of amorphous fibrils, resembling the paired helical (PHF) and/or straight filaments (SFs) typically detected in AD brains [201].