HLA-DRB1 and uveitis: This association correlated strongly with that of HLA‐DRB1 position 13 (P = 2.2 × 10−34), where the amino acids serine (OR 1.6, 95% CI 1.4–1.9) and glycine (OR 1.9, 95% CI 1.5–2.3) conferred the most risk of uveitis (Supplementary Table 3).