Mutant SOD1 led to TNF-α pathway activation in the absence of inflammation in ALS (Carter et al., 2009), an event that may also occur in Schwann cells (Au and Yeh, 2007) based on the results of Traf2 up-regulation in ALS Schwann cells described in our work. This evidence concerns the gene TRAF2 and amyotrophic lateral sclerosis.