To investigate the clinical correlates of CD38+ HLA-DR+ T cells and NK cells, we performed flow cytometry analysis on PBMCs from people in the healthy control group (n = 10), patients with SD stratified by disease state at the time of sampling (inactive SD, n = 11; active SD without MAS, n = 11; MAS, n = 9), and children with other types of JIA (nonsystemic JIA; n = 15). This evidence concerns the gene CD38 and juvenile idiopathic arthritis.