IL10 and systemic lupus erythematosus: Recently, a phenotypic analysis of IL‐10 producing regulatory B cells by single‐cell RNA sequencing was performed in lupus‐prone mice, revealing a loss of marginal zone lineage Bregs in active‐disease lupus‐prone mice.[44] In the present study, we proved the loss of IL‐10 producing MZ B cells as well as the immune regulatory function in regulating Treg induction in the active‐disease stage of the lupus mice.