Intriguingly, the C9-ALS iPSC line 2 and iMN line 2, derived from the same individual with a 2× GGGGCC non-expanded allele, exhibited a mild decrease in C9-V1 and C9-V3 only in the iMNs, suggesting that the expanded allele with hundreds to thousands of repeats can still be partially degraded by the Cas13d system, presumably when local regions of the repeats adopt cleavable conformations under specific cellular environment. Here, C9 is linked to amyotrophic lateral sclerosis.