Region Scores and Candidate Coding Regions (CDSs). The region score is the sum of the individual codon pair scores in an alignment. Human and mouse DNA alignment and codon scores are also shown. Three adjacent nucleotide pairs were treated as 1 codon pair. A high region score indicates that the region might be a CDS because that region contains many codon pairs with high scores. Note that the region scores should be calculated for all frames in both strands.