CCN2 and systemic sclerosis: Robust IL-6/STAT3 signaling in roscovitine-exposed fibroblasts was somewhat surprising because roscovitine not only suppressed IL-6 secretion in both normal and SSc primary fibroblasts (Table 1), but also decreased the expression of fibronectin and CTGF, two proteins that were up-regulated by IL-6 (Figure 1).