As they have been studied in different populations, and ethnicity is a crucial variable to account for with regard to interindividual variability, we suggest that further elucidation of these results, with a much larger sample size, may help in better understanding the roles of factor V Leiden, prothrombin, antithrombin, and fibrinogen gene variants in APS. Here, F2 is linked to autoimmune polyendocrinopathy.