Fallah-Rad et al recently reported that while 25 percent of HER2-positive breast cancer patients (10 out of 42 patients) developed trastuzumab-mediated cardiomyopathy during a three-year prospective clinical study, cardiac biomarkers such as troponin T, C-reactive protein, and brain natriuretic peptide did not change over time [54]. The gene discussed is ERBB2; the disease is cardiomyopathy.