(A) The TRBV polymorphism involving TRBV4-2, TRBV4-3, TRBV6-2, and TRBV6-3. (B) The TRBV polymorphism involving TRBV5-8, TRBV7-8, and TRBV6-9. For both graphs, y axis is the number of individuals. Both plots are based on the full sample of 286 individuals with 73 West Eurasians, 27 Central Asians—Siberians, 45 East Asians, 49 South Asians, and 22 Oceanians. Grey shading indicates that the distribution within a region is significantly different from the global distribution at the 0.01 level in a chi-squared goodness-of-fit test. Our data informs the copy number of these genes, whereas the genomic configuration is our best estimate based on previous studies (see Fig 3).