For example, abnormal pre-tangle tau protein is detected in the LC in Alzheimer's disease from the earliest stages (Braak et al., 2011; Grudzien et al., 2007; Kelly et al., 2017), and severe cell loss is observed in Alzheimer's disease, Parkinson's disease and Progressive Supranuclear Palsy (Theofilas et al., 2017; Surmeier et al., 2017; Kaalund et al., 2020). This evidence concerns the gene MAPT and early-onset autosomal dominant Alzheimer disease.