Another important function of DC is the priming of T‐cell proliferation and the potential of T helper cells polarization [16], We noted that DBC1 deficiency in DCs induced weaken proliferation of both CD4+ and CD8+ T cells (Figure 4D), and Dbc1−/− DC exhibited reduced Th2 cell polarization, but enhanced Treg cell polarization (Figure 4E), which is consistent with the increased Treg cell population in the DC‐specific DBC1 knockout SLE model mice (Figure 3F). This evidence concerns the gene CCAR2 and systemic lupus erythematosus.