The expression of CD45RA but low expression of PD-1 (CD279), TIGIT and other activation markers suggests cluster 2 CD4− cells (13.8% ± 1.6 of SF vs 0.28% ± 0.03 of HC PB and 0.49% ± 0.06 of JIA PB T cells, Fig. 4E and G) could represent TEMRA (terminally differentiated effector memory cells) that re-express CD45RA [37]. The gene discussed is PDCD1; the disease is juvenile idiopathic arthritis.