CD4 and juvenile idiopathic arthritis: The CD3ii group of T-cell clusters mainly encompassed CD4+ T cells (Fig. 4B, H–J), except for cluster 12 which was specific to the inflamed joint (0.23 ± 0.05% of SF CD3+ T cells vs 0.0% of HC/JIA PB CD3+ T cells, Fig. 4E, mainly CD8+, Supplementary Fig. S7C).