Multiple genetic causes of ALS–FTD have been found in the genes encoding RNA binding proteins (RBPs) such as transactive response DNA-binding protein 43 kDa (TDP43), Fused in Sarcoma (FUS), HNRNPA1, and TIA1 which can undergo LLPS in vitro (Molliex et al., 2015; Patel et al., 2015; Mackenzie et al., 2017). This evidence concerns the gene FUS and frontotemporal dementia.