Fig. 2

a Shows how many exon-exon junctions J are found in at least S samples of the 21,504 human RNA-seq samples on the SRA aligned here. It also shows how much evidence for these junctions is found in gene annotation: “fully annotated” (orange) means the junction is in an annotated transcript, “exon skip” (green) means a called junction’s donor and acceptor sites are annotated in distinct junctions, “alternative donor/acceptor” (red) means only one of a called junction’s donor and acceptor sites is in a junction from annotation, and “novel” (blue) means neither donor nor acceptor site is annotated. b and c restrict attention to the 10,311 samples for which 100,000 junctions are discovered in each. b refers to overlaps, where an overlap is any instance where a read maps across a junction