SOD1 and amyotrophic lateral sclerosis: Hsa-miR-34a-3p was found to be specifically downregulated in patients with SOD1-ALS compared to patients with C9orf72-ALS (p = 0.0175), patients with SALS (p = 0.032), and HCs (p = 0.0022), while no statistical significance was found between SALS and HCs (p = 0.151).