GPNMB and amyotrophic lateral sclerosis: Recently, for the first time, we demonstrated the involvement of GPNMB in neuronal cell death induced by the accumulation of abnormal (mutated) proteins as well as possible usefulness of GPNMB as a novel neuroprotective factor in amyotrophic lateral sclerosis (ALS), which is one of the devastating adult-onset neurodegenerative diseases9.