S1PR1 and chronic obstructive pulmonary disease: To shed light on the possible role of S1P in the context of chronic inflammation we selected a selective sphingosine-1-phosphate-1 receptor modulator AUY954, which experimentally reduces heart transplant rejection in vivo. AUY954 led to a significant higher anti-proliferative activity in human lung fibroblasts from COPD patients (DHLF-COPD) in comparison to normal lung fibroblasts (NHLF) (Fig. 5), suggesting that this pathway might be important in ECP and its mode of action.