These pre-clinical data show that a single perinatal injection of ION363 results in a robust and persistent decrease in FUS protein levels for more than 4 months, and that, while the ASO perdures in the spinal cord, the onset of gliosis is delayed and MN loss is prevented, showing the therapeutic potential of FUS silencing—and of this specific FUS-ASO—in the treatment of patients with ALS-FUS. This evidence concerns the gene FUS and amyotrophic lateral sclerosis.