C9 and amyotrophic lateral sclerosis: The results demonstrated that the RNA levels of C9-V1 and C9-V3, which contain the expanded GGGGCC repeat, were significantly decreased by Cas13d-S24 or S30 when compared with NT30 in C9-ALS iPSC line 1 (Supplemental Figure 2B) and C9-ALS iMN line 1 and iMN line 2 (Supplemental Figure 2C).