Confirmation of recent positive selection at the GPX1 locus (3p21). To confirm recent positive selection at the GPX1 locus, we used Haplotter to query the results of a scan for positive selection in the human genome developed using SNP data from the International HapMap project . The vertical line indicates the location of the GPX1 locus. The strong iHS (integrated haplotype score) signal in the Asian (ASN) population at this locus is highly suggestive for recent positive selection. Data is based on the analysis of unrelated individuals from 3 populations: ASN (Han Chinese and Japanese, n = 89), CEU (Northern and Western European, n = 60), and YRI (Sub-Saharan Africans from the Yoruban population, n = 60).