TLR7 and systemic lupus erythematosus: Lower frequencies of GC B cells and plasma cells, together with ameliorated lupus clinical score are observed in the chimeric mice reconstituted with the bone marrow of 3H9 TLR7−/Yaa NZW/BXSB mice in comparison with the bone marrow from 3H9 WT mice, indicating that TLR7 is essential for the spontaneous germinal center response including B cell expansion and diversification in lupus-prone mice [94].