MAPT and Alzheimer disease: Different optical SRM approaches have helped to image both Aβ and tau aggregates in vitro and in cellular models (Pinotsi et al., 2016; Schierle et al., 2016), while STED SRM was used to image immunolabelled tau filaments in postmortem AD brain sections (50 μm) at ∼80 nm resolution (Benda et al., 2016).