Genes encoding cytokines TNF, IL2, IL10, IL6, macrophage migration inhibitory factor (MIF), protein tyrosine phosphatase (PTPN22), signal transducer and activator of transcription-4 (STAT4), solute carrier family-11 (proton-coupled divalent metal ion transporters), member-1 (SLC11A1), natural resistance-associated macrophage protein-1 (NRAMP1) and WNT1-inducible signalling pathway protein-3 (WISP3) have all been associated with JIA [2, 21, 23]. The gene discussed is TNF; the disease is juvenile idiopathic arthritis.