TARDBP and early-onset autosomal dominant Alzheimer disease: Cytoplasmic TDP‐43 accumulation is a hallmark of ALS/FTLD and has been observed in several other neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease and Huntington's disease (Chang et al., 2016; Ling et al., 2013; Ling, Hardy, & Zetterberg, 2015; Markopoulou et al., 2008), yet its contribution to these neurodegeneration remains poorly understood.