Scatter plot of principal components analysis of 435,632 SNPs. Principal component 1 is plotted on the abscissa, component 2 on the ordinate; CEU are designated as open boxes and AJ as smaller open circles. One AJ can be observed in the CEU cluster. Those case removed from analysis following PCA are denoted by an arrow.
Olshen et al. BMC Genetics 2008 9:14 doi:10.1186/1471-2156-9-14