C9orf72 and amyotrophic lateral sclerosis: To further establish the functional relevance of the IL18RAP 3′UTR variants, we edited the genome of human iPSCs donated by individuals with ALS with a C9orf72 repeat expansion65 (National Institute of Neurological Disorders and Stroke (NINDS)/Coriell code ND10689, ND12099; Supplementary Table 8), to include two point mutations that recapitulate the most prevalent variants (chr2:103068691 C > T (V1) and chr2:103068718 G > A (V3)) in the IL18RAP 3′UTR sequence (Fig. 4a).