SOD1 and amyotrophic lateral sclerosis: Many studies [41–44] have shown that different pathways (including the mitochondrial apoptosis pathway, the glutamate excitotoxicity pathway, and the HGF overexpression pathway) increase the levels of apoptotic proteases and decrease the expression levels of XIAP protein in the spinal cord, which is closely related to motor neuron degeneration in the process of ALS-related apoptosis due to mutant SOD-1.