Non-canonical miR examples from Ciona. (a) A classic example of mirtron Ci-mir-2219-2 shows the miR and miR* products are produced from the precisely spliced intron from gene ci100134440. (b) In some cases, only one of the miR/miR* products abuts the splice junction, while the other product is fully inside the intron. A so-called half-mirtron example, Ci-mir-2227, is represented. (c) Ci-mir-2233 produces a miR/miR* pair from a perfectly structured hairpin, which overlaps with a protein coding exon in the gene ci0100152310.