Integrated single-cell RNA and immune repertoire analysis of 177,259 peripheral blood mononuclear cells (PBMCs) from healthy donors and SLE patients (including active LN and non-nephritis controls) revealed LN-specific circulating immune signatures, including κ light-chain preference in naive B cells and distinct clonal expansion in CD8<sup>+</sup> effector T cells. The gene discussed is CD8A; the disease is systemic lupus erythematosus.