With this multifaceted genetic background and bearing in mind also the recently proposed “multistep” model of disease in ALS consistent with a six-step process, in the patients carrying genetic mutations associated with ALS, the number of steps necessary to start the neurodegenerative process has been shown to be reduced compared to cases without mutation (i.e., lower for SOD1, intermediate for C9orf72, and higher for TARDBP) [7]. Here, C9orf72 is linked to amyotrophic lateral sclerosis.