The ALS-associated mutated forms of TDP-43, FUS, TIA-1, and hnRPNA1 accelerate the conversion of the liquid droplets into a solid aggregated-like state in vitro, while they all confer rigidity to SGs in ALS cell models, thereby delaying their disassembly kinetics and favoring the co-aggregation of SGs with other misfolded aggregate-prone proteins (Ganassi et al., 2016; Taylor et al., 2016; Mateju et al., 2017). The gene discussed is FUS; the disease is amyotrophic lateral sclerosis.