Although this study used N10-N14 backcrossed mice that are expected to carry ≤0.1% genes from the 129/B6 β2m° or CD1d° founders, there remains the possibility that our results reflect the alteration of linked gene(s) during the backcross of the mutated β2m or CD1d 129 locus onto the lupus genetic backgrounds. The gene discussed is B2M; the disease is systemic lupus erythematosus.