• exon
  • Several types of different alternative splice forms exist including exon skipping, differential splicing of exons at their 3'- or 5'-end, intron retention, and mutually exclusive splicing. (biomedcentral.com)
  • The first type is exon skipping, in which an exon, also called cassette exon, is spliced out of the transcript together with its flanking introns. (biomedcentral.com)
  • The fourth type is intron retention in which part of an exon is either spliced (like a regular intron) or retained in the mature mRNA transcript. (biomedcentral.com)