C9orf72 and amyotrophic lateral sclerosis: Among ALS patients, 90–95% are sporadic, with mutations in the genes C9ORF72, SOD1, FUS, etc. Strikingly, about 97% of these ALS patients and 45% of FTLD patients exhibited TDP-43 aggregation, implicating its pathogenic role in causing the motor neuron diseases [175].