SOD1 and amyotrophic lateral sclerosis: We did not find any change in basal [Ca2+]c upon ALS mutant SOD1 expression (Fig. 2 and Supplementary Material, Fig. S2) and consistent with a Ca2+-independent mechanism both wild type and Ca2+ insensitive mutant Miro1 were able to restore axonal transport of mitochondria in ALS mutant SOD1 expressing neurons (Fig. 4).