CD38 and systemic lupus erythematosus: MC05 (CD27−CD28−CD38−CD57+CD127+HLA-DR−), which differed in CD38− and CD127+ from MC01, was the lowest in SLE (HCs: 3.803%; RA: 2.407%; SSc: 4.731%; SLE: 1.289%) (Figure 5B).