SOD1 and mild neurocognitive disorder: Whether APLP2 also has a role in MND was investigated by crossbreeding the APLP2−/− mouse with the SOD1-G37R mouse and this generated viable progeny expressing SOD1-G37R:APLP2−/− and SOD1-G37R:APLP2 ± mouse lines which lacked both or one APLP2 allele, respectively.