Our findings revealed that the number of CD1c+DCs in PBMCs in SLE patients decreased compared with healthy controls and RA patients (Supplementary Fig. 1), and the number of CD1c+DCs was negatively correlated with the SLEDAI score and LN-related indexes (Fig. 1e, f, g, h, i), indicating the crucial role of this tolerogenic DC subset in the pathogenesis of SLE, especially in patients with renal abnormalities. This evidence concerns the gene CD1C and rheumatoid arthritis.