FUS and familial amyotrophic lateral sclerosis: Fused in sarcoma (FUS) is a DNA/RNA-binding protein in which mutations and altered post-translation modifications (especially hypomethylation of arginine residues) give rise to pathological condensates that cause FUS-associated frontotemporal lobar degeneration (FTLD-FUS) and familial amyotrophic lateral sclerosis (fALS-FUS) [1–3].