In support of this idea, altered cellular levels of PRRs can cause autoimmunity in mammals, as illustrated by duplication of the Tlr7 gene in mice, which results in systemic autoimmunity modelling the clinical symptoms seen in the human autoimmune disease systemic lupus erythematosus (SLE) [48,49]. The gene discussed is TLR7; the disease is systemic lupus erythematosus.