VAPB and amyotrophic lateral sclerosis: Interestingly, PDI colocates with inclusions in motor neurons of SOD1G93A mice [7], in human ALS patients [38], and also with inclusions formed by vesicle associated membrane protein-associated protein B (VAPB) in a Drosophila melanogaster model of a rare familial form of ALS caused by mutant VAPB [78].