TGF-β1 did not alter prostacyclin production in fibroblasts from healthy controls (n = 9) and prostacyclin synthesis after TGF-β1 stimulation was significantly higher (p < 0.05) in lung fibroblasts from patients with COPD compared to control subjects (Figure 2A). The gene discussed is TGFB1; the disease is chronic obstructive pulmonary disease.