C9orf72 and amyotrophic lateral sclerosis: In both datasets we identified dramatically less retained introns in ALS mutants compared with control (C9orf72: 7,925 versus 14,937 [47% less, Supplementary Figure S3C]; SOD1: 3,602 versus 7,842 [54% less, Supplementary Figure S3E] respectively, Figure 1C).