There were no significant differences between the mean normalized serum DDX43 protein levels in different groups based on body mass index, menopausal status, tumor size (T1 vs. T3-4), tumor-node-metastasis (TNM) stage, lymph node stage, mitosis score (1 vs. either 2 or 3), tubular formation score, histological grade, tumor grade, hormonal receptors, HER2 Family, triple-negative phenotype, NPI, biological classes and NPI+ for the biological classes (Results are not shown). The gene discussed is ERBB2; the disease is neoplasm.