Etanercept (ETN), an inhibitor of tumor necrosis factor alpha (TNFα), was shown to be safe and efficacious in children with polyarticular JIA who received up to 8 years of continuous treatment [15, 16], but evidence of long-term benefits in the JIA categories of eoJIA, ERA, and psoriatic arthritis has been limited [17, 18]. This evidence concerns the gene TNF and juvenile idiopathic arthritis.