Nazzareno Galiè1, Vallerie V McLaughlin2, Lewis J Rubin3, Gérald Simonneau4. 1. Dept of Experimental, Diagnostic and Specialty Medicine-DIMES, University of Bologna, Bologna, Italy nazzareno.galie@unibo.it. 2. Dept of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI, USA. 3. Division of Pulmonary and Critical Care Medicine, University of California, San Diego, CA, USA. 4. Hôpital Universitaire de Bicêtre, Université Paris-Sud, Le Kremlin Bicêtre, France.