When investigating the correlations between mRNA levels of ET-1 and the cytokines that were up-regulated in alveolar macrophages from HF patients (i.e., TNFα and IL-6) and clinical and hemodynamic parameters in these patients, we found a strong trend toward correlation between IL-6 mRNA levels and LV function [LV ejection fraction (EF); r = −0.53, p = 0.06]. This evidence concerns the gene IL6 and hydrops fetalis.