Interleukin 1 receptor-associated kinase 1 (IRAK1; located at Xq28) and toll-like receptor 7 (TLR7; located at Xp22.2) are both such X chromosomal genes for which both human association studies and mechanistic experiments in mice support roles in lupus pathogenesis (39, 40), but their distance from the AR gene (at Xq12) would certainly seem to preclude such linkage disequilibrium. Here, TLR7 is linked to systemic lupus erythematosus.