IRF8 and systemic lupus erythematosus: To validate the robustness of our unbiased analysis, we confirmed our ability to detect SLE-associated alterations in the frequency of rare cell populations, such as plasmablasts (CD20–CD19intCD27hiCD38hi) (27) and plasmacytoid dendritic cells (CD123+HLA-DR+IRF8+) (34) (Supplemental Figure 1H).