FOCUS-C9 is a phase Ib/IIa trial of the intrathecal administration of ASO (WVE-004-001) that promotes RNase H-mediated degradation of C9ORF72’s pathogenic mRNA variants associated with ALS or FTD and spares the normal C9ORF72 V2 variant in neurons (NCT04931862). The gene discussed is C9orf72; the disease is amyotrophic lateral sclerosis.