CR1 and autoimmune disease: SLE is a clinically heterogeneous autoimmune disorder with diverse genetic causes [36], and the genes encoding HLA class II, mannose binding protein (MBP), TNFα, the T cell receptor, interleukin 6 (IL-6), CR1, immunoglobulin Gm and Km allotypes, FcgRIIA and FcgRIIIA (both IgG Fc receptors), and heat shock protein 70 are thought to be associated with SLE [37].