NRG1 and amyotrophic lateral sclerosis: The relevance of the NRG1/ErbB pathway in MN diseases has been further underlined by the discovery of a new type of familial ALS caused by a loss of function mutation of ErbB434, and by the reported neuroprotective effects of NRG1 supplementation35 and/or altered NRG1 expression36 in ALS mice.