A translocation from the X chromosome onto the Y chromosome causes overexpression of the translocated genes, which includes the ssRNA-recognizing TLR7 member of the TLR family of receptors in male mice bearing the y-linked autoimmune accelerating (Yaa) locus, which is sufficient to enhance TLR7-mediated activation of innate immune responses and lupus development29–31. The gene discussed is TLR7; the disease is systemic lupus erythematosus.