TNFSF13B and nephritis: BAFF transgenic C57BL/6 mice (BAFF-tg) overexpress B-cell activating factor, which results in B-cell hyperproliferation and systemic autoimmunity with lymphocytic infiltration in their salivary and lacrimal glands, decreased saliva production, SLE-like nephritis and increased production of rheumatoid factor and anti-DNA autoantibodies.