At the transcriptomic level, Tph cells from RA and oligo JIA have a mutual gene expression program characterized by upregulation of multiple genes associated with B cell help such as PDCD1, CXCL13, CD40LG, SH2D1A/SAP and BATF (9, 47, 50). Here, CXCL13 is linked to juvenile idiopathic arthritis.