CD4 and juvenile idiopathic arthritis: To study whether the same expanded T cell clones infiltrate multiple joints, we performed TCR sequencing for similar numbers of CD3+CD4+CD25+CD127low Tregs and CD3+CD4+CD25−CD127+ non-Tregs sorted from affected joints of JIA patients, derived from the same donors and time points as the ones used for CyTOF analysis regarding the first two patients.