The 5-year distant-metastasis-free survival (DMFS) rate was 81.4% for patients with elevated HER2 ECD and 93.6% for those with normal HER2 ECD (log-rank P < 0.001; Figure 4A); and corresponding 5-year breast-cancer-specific survival (BCSS) rates were 85.3% and 95.1% (log-rank P < 0.001; Figure 5A). The gene discussed is ERBB2; the disease is breast cancer.