This study evaluates five candidate biomarkers high-sensitivity troponin I (hs-Tn I), high-sensitivity C reactive protein (hs-CRP), interleukin 6 (IL-6), uric acid (U.A), and N-terminal pro b-type natriuretic peptide (NTproBNP) measured during the treatment of early HER2+ breast cancer, which refers to non-metastatic (M0) breast cancer according to National Comprehensive Cancer Network NCCN, and American Society of Clinical Oncology ASCO. This evidence concerns the gene IL6 and breast cancer.