Regarding SULT1A1, an enzyme catalysing the sulfonation of many phenolic molecules, including endogenous compounds (e.g. estradiol and iodothyronines), environmental xenobiotics and drugs (38), its downregulation in the plasma of patients with inactive systemic juvenile idiopathic arthritis (39) and upregulation in the sera of patients with ulcerative colitis have been reported (40). This evidence concerns the gene SULT1A1 and juvenile idiopathic arthritis.