In ALS mouse and cell models, overexpression of PDI decreases both the accumulation of SOD1 aggregates and neuronal cell death, whereas inhibition of PDI using bacitracin or siRNA knockdown increases the formation of aggregates (Atkin et al., 2006, 2008; Walker et al., 2010; Jeon et al., 2014). This evidence concerns the gene P4HB and amyotrophic lateral sclerosis.