After stimulation with anti-CD3 and anti-CD28 antibodies, a considerably higher concentration of IL-22 could be detected in PBMCs from BD patients with active uveitis (1382±489 pg/ml) compared to that observed in BD patients without active uveitis (778±211 pg/ml, p<0.001), AAU patients (911±271 pg/ml, p = 0.011) or normal controls (886±190 pg/ml, p = 0.004) (Fig. 1A). Here, CD28 is linked to uveitis.