The relative contributions of B cell-intrinsic TLR7 and TLR9 on autoimmunity were addressed by Jackson et al. This group generated mixed bone marrow (BM) chimeras by adoptively transferring BM from wild type, Wiskott–Aldrich syndrome (WAS) protein-deficient, Was-deficient-Tlr7-deficient, or Was-deficient-Tlr9-deficient mice with μMT BM (20:80) into lethally irradiated μMT recipient mice (20). Here, TLR9 is linked to Autoimmunity.