SLC6A4 and Behcet disease: Validating these preliminary candidate genes by searching for at least two studies showing statistically significant positive association (Bonferroni corrected p-value ≤ 0.05) with both BD and TUD, we found that only COMT [42-47], SLC6A3 [48-57], and SLC6A4 [58-63] meet the requirement.