Plasma levels of TnI have been used as a prognostic marker of cardiac disease for high dose chemotherapy,[1,2] especially for anthracyclines.[1] However, 2 trials found that in left breast cancer patients, left ventricular ejection fraction (LVEF) did not significantly change after radiotherapy, and was not correlated with TnI levels.[3,4] Hence, TnI is not considered for biomarker to cardiac damage of breast cancer patients.[5–9] So, what about BNP? This evidence concerns the gene NPPB and breast cancer.