IL6 and systemic sclerosis: Indeed, when SSc fibroblasts were cocultured with healthy control B-cells stimulated by BAFF (inducing the secretion by B-cells of pro-fibrotic cytokines such as IL-6, CCL-2, TGF-β1), they produced tissue inhibitor of metalloprotease-1 (TIMP-1), collagens, and α-smooth muscle actin (α-SMA) (10).