Transcripts that undergo significantly changed intron retention in C9high patient samples encode proteins functionally enriched in cellular protein quality control pathways. (A) Gene Ontology enrichment analysis of transcripts that undergo significantly changed intron retention in C9high patient samples compared to normal controls. (B) Volcano plots showing the magnitude and direction of changes in intron retention for introns embedded in transcripts that encode proteins functioning in the proteasomal pathway, the autophagy pathway, and the splicing regulatory pathway, respectively.