PTPN2 and juvenile idiopathic arthritis: In order to determine functional clusters, that is, distinct groups of protein:protein interactions in relation to the key prioritised genes, KSR1 for RF-ve polyarticular JIA and Protein tyrosine phosphatase, non-receptor type 2 (PTPN2) for oligoarticular JIA the MCODE algorithm was applied to the JIA interactome (Figure 1E).