C9orf72 and frontotemporal dementia: To determine whether KPNB1 can also reduce the aggregation of cytoplasmically mislocalized endogenous TDP-43, we used a C9ALS/FTD disease model based on expression of a C9orf72 repeat expansion-derived poly(GR) dipeptide repeat protein, which has been shown to induce endogenous TDP-43 mislocalization in mice [40, 41].