Similarity comparison of the cag -PAI regions of strains B8, HPAG1, P12, and 26695. The image shows the annotation of genes inside the cag-pathogenicity island of the four H. pylori genomes. Orthologous groups of genes are drawn in the same color. Each gene is labeled with its 'gene' feature tag from the Genbank annotation file. If for a given gene, a 'gene' feature tag is missing in the Genbank file in the first place, the terminal four characters of the 'locus-tag' feature tag are used as labels instead. Genes which do not show significant sequence similarities to any genes in the other genomes (singletons) are drawn with no fill color but a red stroke color. The image was created by the software AnnotationSketch .