C9orf72 and amyotrophic lateral sclerosis: On the other hand, the pathogenic mutation associated with TAR DNA-binding protein 43 (TDP-43), superoxide dismutase 1 (SOD1), fused in sarcoma/translocated in sarcoma (FUS), and C9ORF72 causes protein misfolding and the accumulation of misfolded protein aggregates, which contribute to motor neuronal loss in ALS [163,164].