SOD1 and mild neurocognitive disorder: In contrast, CSA type II muscle fibres, the most vulnerable type of muscle fibres in MND pathogenesis [58–60], were significantly reduced by ~ 40% in the male SOD1-G37R:APLP2−/− mouse compared to both SOD1-G37R:APLP2+/+ and SOD1-G37R:APLP2 ± mice groups (Fig. 10C).