Antisense therapy is the process by which synthesized strands of nucleic acids are used to bind directly and specifically to the mRNA produced by a certain gene, which will inactivate it. Antisense oligonucleotides (ASOs) are commonly used to target C9orf72 RNA of the G-quadruplex GGGGCC expansion repeat region, which has lowered the toxicity in cellular models of C9orf72. ASOs have previously been used to restore normal phenotypes in other neurological diseases that have gain-of-function mechanisms, the only difference is that it was used in the absence of G-quadruplex expansion repeat regions.