PTPN22 and juvenile idiopathic arthritis: The combined analysis of all available JIA cases identified eight loci reaching genome-wide significance (p≤5 x 10-8), of which seven have previously been reported and recognised by the notable gene at each locus: MHC (6p25-p34), PTPN22 (1p13.2), STAT4 (2q32.2-q32.3), ANKRD55 (5q11.2), ATXN2 (12q24.12), PTPN2 (18p11.21), and TYK2 (19p13.2) (figure 1 and table 1).6 The strongest association was found to SNPs within the extended MHC region (chr6: 28 477 797 to 33 448 354).