A phylogenetic tree constructed based on the complete amino acid sequence of H. pylori CagA protein in 22 isolates from Southern Vietnam (VietnamHP no. 7, 6, 17, 16, 4, 23, 27, 33, 2, 5, 15, 31, 24, 25, 20, 3, 8, 36, 22, 14, 32, 28 [given in the order shown in Tables 2 and 3]) compared with complete amino acid sequence of H. pylori CagA protein in 54 isolates from the GenBank database, including Japan (32 strains, 14 with the Western CagA type from Okinawa and 18 with the East Asian CagA type from Fukui), China (5 strains), India (2 strains), Australia (4 strains), Europe (4 strains), and America (7 strains). The length of the horizontal bar indicates the number of amino acid substitutions per site.