We now present experimental evidence both in vitro and in vivo that accumulating cytosolic TDP-43 causes the nuclear decrease and cytoplasmic accumulation of KPNA4, cellular phenotypes that also characterise KPNA4 pathology seen in the brain and spinal cord of FTD (Solomon et al., 2018) and ALS patients (herein). Here, TARDBP is linked to frontotemporal dementia.