Adult breast cancer with low or medium risk by baseline Heart Failure Association and International Cardio-Oncology Society (ICOS) cardiotoxicity assessment,25 who have completed HER2-targeted therapy, demonstrate recovered HER2-targeted therapy-related cardiac dysfunction (left ventricular ejection fraction>50% for 6 months, no heart failure symptoms and N-terminal pro-B-type natriuretic peptide and continued heart failure treatment since then (at least one of a beta-blocker and/or ACE inhibitor/angiotensin receptor blocker). The gene discussed is ERBB2; the disease is breast cancer.