In another example, Kunze et al. studied the pathogenesis of amyotrophic lateral sclerosis (ALS), which is a common motor neuronal disease, by co-culturing neurons and astrocytes with wild-type or mutated superoxide dismutase enzyme 1 (SOD1) for demonstrating oxidative stress on cortical neurons [71]. Here, SOD1 is linked to amyotrophic lateral sclerosis.