This group included well-established (e.g., NT-proBNP) and more recently recognized (e.g., ST2) plasma biomarkers of HF, together with factors recently associated with this disease (e.g., GDF15, IGFBP7, TfR) and one factor that was only just now linked to HF (galectin-4) [13]. Here, NPPB is linked to hydrops fetalis.