Table 2 shows the detailed comparison between plasma total immature SP-B, mature SP-B, SP-A, SP-D and RAGE levels in HF patients when categorized for HF severity as defined by NYHA class, DLCO, peak VO2, VE vs. VCO2 slope, and BNP (66 cases) levels. This evidence concerns the gene SFTPB and hydrops fetalis.