This analysis corroborated similar overexpression levels of ERp57 and SOD1 in double transgenic mice compared to single transgenic littermates, along with induction of endogenous copper chaperone for SOD1 (Ccs) in ALS mice (Fig. 4g, Additional file 1: Fig. S5 and Additional file 2: Table S2). Here, CCS is linked to amyotrophic lateral sclerosis.