ITGAX and juvenile idiopathic arthritis: Cluster 16 were CD16highCD14low cells representing pro-inflammatory non-classical monocytes in blood [20], which were at a low frequency or undetected in SF (0.14 ± 0.04% of SF CD11c+ cells vs HC PB 10.8 ± 1.9% and JIA PB 18.0 ± 1.6%, mean ± SEM, Fig. 2C and D).