C9orf72 and amyotrophic lateral sclerosis: To evaluate the portion of unspliced and cryptically spliced transcripts from total C9orf72 transcripts in normal and C9-ALS iPSCs, we counted reads that overlapped the 5’ boundary of exon 2 and contained either the terminus of authentic or cryptic exons as well as unspliced intron transcripts (S9 Fig).