ITGAM and systemic lupus erythematosus: In a subsequent study, they further split CD20+CD27+CD43+ human “B-1” cells into CD11b- “secretor” cells (i.e. primarily secreting natural antibodies) and CD11b+ “orchestrator” cells that were expanded in SLE patients, and spontaneously secreted IL10, but could enhance T-cell proliferation and modulate T-cell activation (112, 113).