PDIA3 and amyotrophic lateral sclerosis: To define the functional impact of increasing ERp57 levels on ALS onset and progression, we crossed SOD1G93A mice with a transgenic line overexpressing ERp57WT under the Prion promoter previously generated in our laboratory [24, 25] to obtain SOD1G93A/ERp57WT double transgenic mice and control littermates (Fig. 1a).