Fig. 5

Back splicing occurs from Exon 2 to Exon 1 which generates a circle. The blue node with symbol # is the anchor node of donor and the blue path in graph represents the donor (Exon 2) by tracing backward from the anchor node. “Brief-path-donor” contains eight blue nodes in path, including four premium nodes. Green path in graph represents the acceptor (Exon 1) by tracing forward from anchor node. “Brief-path-acceptor” contains eight green nodes in path, including four premium nodes. Six nodes from the brief path of donor and acceptor can find hits in reads respectively. Since there are more than 70% hits and the distance between nodes 6 and 7 is shorter than 3 bps, this reads is considered to support the back splicing from Exon 2 to Exon 1