The concept that TLR7 dosage is positively associated with SLE-provoking signaling could be a potential explanation for the strong female bias observed in SLE, the 14-fold higher incidence of SLE in 47 XXY males (Klinefelter syndrome) compared to 46 XY males, and the lower incidence of SLE in 45 XO females (Turner syndrome) [26]. This evidence concerns the gene TLR7 and systemic lupus erythematosus.