Furthermore, quantification of RNA foci in the nuclei of patient cells revealed no significant difference in the treatment with Cas13d-S24 and Cas13d-S30 compared with the non-targeting control treatment with Cas13d-NT30 in each C9-ALS patient cell line (Supplemental Figure 3D), confirming the limited ability of the CRISPR/Cas13d system to degrade the GGGGCC repeat RNAs that are trapped as aggregates within the RNA foci. Here, C9 is linked to amyotrophic lateral sclerosis.