FLI1 and systemic lupus erythematosus: We demonstrate that adoptive transfer of MRL/lpr Fli1+/+ or Fli1+/- T cells and B cells into Rag1-deficient mice results in significantly decreased serum immunoglobulin levels in animals receiving Fli1+/- lupus T cells compared to animals receiving Fli1+/+ lupus T cells regardless of the genotype of co-transferred lupus B cells.