Inspired by the finding that over-expression of mutant hSOD1 induces ALS-like symptoms in mouse (Gurney et al., 1994; Wong et al., 1995), we generated mouse ESC lines expressing high levels of wild type (WT) hSOD1, and hSOD1 with A4V or G93A mutations, both of which are genetic causes of familial ALS (Rosen, 1993; Gurney et al., 1994; Kiskinis et al., 2014). The gene discussed is SOD1; the disease is amyotrophic lateral sclerosis.