C9orf72 and Huntington disease: In patients in the early stages of Huntington’s disease, another repeat expansion disorder displaying striatal pathology, administration of antisense oligonucleotides resulted in dose-dependent reductions in concentrations of pathogenic mutant protein [36], while targeting G4 secondary structure was successfully applied to ameliorate the pathology of extended C9orf72 hexanucleotide repeats, related to amyotrophic lateral sclerosis/frontotemporal dementia [37].