TNFSF13B and systemic lupus erythematosus: For the immunological basis, this effect was possibly mediated by a synergistic effect of IL-4, IL-6, IL-13, and BAFF, together with the constitutive expression of CD40L (35, 44), as confirmed by our observation of a high expression level of these effectors by basophils of SLE patients (Figure 3C).