VAPB and amyotrophic lateral sclerosis: PDI also co-localizes with inclusions formed by other ALS-linked proteins, TDP-43 (Honjo et al., 2011; Walker et al., 2013), FUS (Farg et al., 2012) and vesicle associated membrane protein (VAPB) (Tsuda et al., 2008), implying that PDI is linked to general protein misfolding in ALS.