The excitotoxic hypothesis implies that alterations of some of the multiple receptors, ion channels, and calcium-binding proteins (CBPs), could be the result of some of the ALS mutations above described and the aggregation of pathological proteins (Appel et al., 2001; Van Den Bosch et al., 2006; Bezprozvanny, 2009; Grosskreutz et al., 2010; De Diego et al., 2012). The gene discussed is SRPX2; the disease is amyotrophic lateral sclerosis.