XPO1 and frontotemporal dementia: Some amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) patients also have expansion repeats in the ATXN2 gene that result in the production of polyQ proteins.37, 38 They have been shown to exhibit defective nuclear export activity, likely regulated by XPO1 function.39, 40, 41, 42 A series of pharmacological inhibitors of XPO1 nuclear export function have been developed initially for cancer therapies.43