Correlation between North-South population differentiation axis and number of systemic lupus erythematosus risk alleles. Mean number of SLE risk alleles per sample collection is represented against the North/South score (N/S score) obtained in the same samples. Collection letter codes are as in Table 1.
Alonso-Perez et al. Arthritis Research & Therapy 2012 14:R94 doi:10.1186/ar3818