Similar to MC01, MC13 (CD27+CD28+CD38+CD57−CD127−HLA-DR+) was the highest in SLE (HCs: 0.866%; RA: 1.075%; SSc: 0.991%; SLE: 1.809%): CD27+CD28+ and CD57−. The gene discussed is CD38; the disease is systemic lupus erythematosus.