CD38 and rheumatoid arthritis: The other three MCs that dominated in SLE were MC07 (CD38+CD197−HLA-DR+) (HCs: 5.081%; RA: 7.228%; SSc: 5.179%; SLE: 13.378%), MC08 (CD38+CD57−CD197−HLA-DR−) (HCs: 3.209%; RA: 3.461%; SSc: 5.072%; SLE: 12.104%), and MC10 (CD38+CD197+) (HCs: 1.963%; RA: 2.981%; SSc: 2.501%; SLE: 6.404%) (Figure 6B).