Interestingly, a functional polymorphism in the TLR7 gene resulting in the elevated TLR7 expression, predisposed the male gender to SLE (Shen 2010) The Y-linked autoimmune accelerating (Yaa) locus which is located on the Y chromosome and contains a cluster of the X-linked genes translocated into the Y chromosome, confers susceptibility to the autoimmune disease in male mice. This evidence concerns the gene TLR7 and systemic lupus erythematosus.