GDF15 and heart failure: New biomarkers such as soluble suppression of tumorigenesis-2 (sST2), growth/differentiation factor 15 (GDF-15), heart-type fatty acid-binding protein (H-FABP), insulin-like growth factor binding protein 2 (IGF-BP2), and soluble urokinase-type plasminogen activator receptor (suPAR) are starting to be mentioned together with classical biomarkers such as brain natriuretic peptide (BNP) and cardiac troponin I (cTnI) because of their potential for an adequate diagnosis of cardiovascular diseases, including myocardial infarction [13,14] or heart failure [15,16].