Algorithm and exon slices. (a) Algorithm flow chart. (b) The exon slices were determined by the genomic structures of the transcript isoforms having overlapping exons. The lower weight was applied for the shorter exon slice. This example shows four exon slices (s1-s4) obtained from three transcript isoforms. The observed RPKM of the smallest exon slice (s3) was smaller than 10 because its length is small.