As has been proposed in a previous study of aging CYP1B1 knockout mice that developed glomerulonephritis and histiocytic sarcoma, defects in mononuclear cell function are present in many autoimmune prone strains of mice, and may play a role in the histiocytic proliferations noted in these huTLR7/8 mice as well [43]. This evidence concerns the gene CYP1B1 and histiocytic sarcoma.