SOD1 and amyotrophic lateral sclerosis: The findings of zinc-deficient SOD1 localized to the ventral horn in human ALS patients (Trist et al., 2022) and in the spinal cord of symptomatic G93A mice (Hale et al., 2025) provide direct in vivo evidence supporting this mechanism of selective motor neuron vulnerability through spatially restricted zinc loss from SOD1.