PTPN22 and juvenile idiopathic arthritis: Expression of PTPN22 R620W is associated with increased risk of T1D,60 rheumatoid and juvenile idiopathic arthritis (RA/JIA),61–64 systemic lupus erythematosus (SLE),65 Grave’s disease66 and pernicious anemia,67 but not psoriasis63,68 or MS.63