32 Humbert Humbert M M Monti Monti G G Brenot Brenot F F Sitbon Sitbon O O Portier Portier A A Grangeot-Keros Grangeot-Keros L L et al et al Increased Interleukin-1 and Interleukin-6 Serum Concentrations in Severe Primary Pulmonary Hypertension Increased Interleukin-1 and Interleukin-6 Serum Concentrations in Severe Primary Pulmonary Hypertension Am J Respir Crit Care Med Am J Respir Crit Care Med 1995 1995 151 151 5 5 1628 1628 1631 1631 10.1164/ajrccm.151.5.7735624 10.1164/ajrccm.151.5.7735624 7735624 7735624. This evidence concerns the gene IL6 and idiopathic pulmonary arterial hypertension.