TNNI3 and cancer: In addition to LVEF monitoring, both the European Society of Cardiology (ESC) and the American Heart Association (AHA), as well as the European Society for Medical Oncology (ESMO), in their guidelines regarding cardiotoxicity of different cancer treatments, recommend the measurement of circulating cardiac biomarkers, such as cardiac troponin I (cTn I) and the amino-terminal fragment of the prohormone brain-type natriuretic peptide (NT-proBNP), to evaluate the cardiac dysfunction induced via HER2-targeted therapies [18,21,22].