Extracellular matrix remodeling by human cardiac myofibroblasts. TGFβ1 stimulates both atrial (A) and ventricular (B) myofibroblast-mediated collagen gel contraction as compared to controls. This effect was inhibited in the presence of LMW-FGF-2. Data presented were obtained from multiple individual experiments (4 experiments, total N = 14 per group for A; 3 experiments, total N = 8 per group for B) and all values were normalized to the corresponding control groups. Bars represent mean ± SD; *p < 0.01, **p < 0.001; abbreviation: CF – cardiac fibroblasts.