For example, immunosuppressive steroids decrease IL-6 levels and reduce pulmonary artery pressures [29]; high levels of TNF-α suppress the mRNA expression of the vasodilating prostacyclin and increase pulmonary vascular reactivity [30, 31], and in the aforementioned studies done by Dulce et al. and Tiago et al., the pulmonary hemodynamics and the right ventricular hypertrophy in PH rats were ameliorated by antagonizing the overactivated IL-6 and TNF-α systems. This evidence concerns the gene IL6 and Right ventricular hypertrophy.