FKBP11 and systemic lupus erythematosus: Thus, to understand the biological significance of the overexpression of FKBP11 in B cells during human SLE, we created lentiviral transgenic mice reproducing the high level expression of FKBP11. The results show that variation in the expression of this single gene is able to induce two phenotypic traits of human lupus: B cell tolerance breakdown and initiation of plasma cell differentiation.