Despite previous biophysical studies have examined the GQ structures adopted by varied lengths of C9-HRE DNA sequences with no more than five repeats [37,38,39,40,41], the structures of those bearing more than one tandem GQ motif that are highly associated with neurodegenerative diseases are still unclear, which hampers the strategy of screening small-molecule ligands to target the C9-HRE region. Here, C9 is linked to neurodegenerative disease.