CTGF knock-down with shRNA inhibits TGFb-dependent cell proliferation of cardiac fibroblasts. Primary cardiac fibroblasts (P) were infected with lentiviruses encoding CTGF shRNAs (h2 or h5) or with a lentivirus expressing a scrambled shRNA as control. Cells were serum starved for 24 hrs and replated in medium containing growth supplements and the indicated concentrations of TGFb (TGFb). Panel A: CTGF protein expression was measured after 7 days. Panel B: Cell proliferation was measured by Cyquant at the indicated timepoints.