The diureticum triamterene is another compound which might be useful for the therapy of SLE because it is able to induce IDO activity in mDCs and such IDO+ DCs have been described to induce fully functional Foxp3 positive CD4+CD25+ T cells (Ghosh and Branch, 1975; Chung et al., 2009). Here, IDO1 is linked to systemic lupus erythematosus.