SOD1 and amyotrophic lateral sclerosis: Liu et al. demonstrated that the reduction of mitochondrial fusion proteins (Mfn1 and Opa1) and the steady-state activity of Drp1 and Fis1 are important for mitochondrial fission by altering the balance of mitochondrial morphology in ALS mutant (G93A SOD1) transgenic mice (Figure 2B) [58].