Amyotrophic lateral sclerosis is etiologically associated with the aberrant amassing of misfolded proteins, including SOD1 (superoxide dismutase 1), TARDBP/TDP‐43 (TAR DNA binding protein), or with the translation of dipeptide repeat proteins from the C9orf72 expanded repeat (the latter accounting for the most common variant of ALS) in motor neurons. This evidence concerns the gene C9orf72 and amyotrophic lateral sclerosis.