The B6.Sle1yaa lupus model is driven by the Sle1 lupus susceptibility locus derived from lupus-prone NZB2410 mice in combination with the Y chromosome autoimmune accelerator locus whose effects are attributed to Tlr7 duplication (Pisitkun et al., 2006; Subramanian et al., 2006). The gene discussed is TLR7; the disease is systemic lupus erythematosus.