UPF1 and frontotemporal dementia: On the other hand, improving the UPF1 function through overexpression is generating a large interest in cell and Drosophila models of C9RF72-ALS/FTD (Xu et al., 2019; Ortega et al., 2020; Zaepfel et al., 2021) as well as in TDP-43/FUS-ALS (Barmada et al., 2015).