Left: Independent snoRNA gene unit, which is the predominant snoRNA gene organization in e.g. yeast. Middle: snoRNA hosted in the intron (red line) of a protein-coding gene. The green boxes indicate coding regions called exons. This is the predominant snoRNA gene organization in e.g. humans. Right: In the described study it was demonstrated that a specific intron-hosted snoRNA controls the splicing of its host transcript.