TARDBP and frontotemporal dementia: TAR DNA‐binding protein (TDP‐43) is the major aggregating protein in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) patients and also forms pathological aggregates in up to 50% of Alzheimer's disease patients (Neumann et al, 2006; Josephs et al, 2014).