Spearman correlation coefficients between pathological tumor size and measurements by MRI and US were 0.55 and 0.51 for all tumors, 0.43 and 0.51 for HR+/HER2+, 0.67 and 0.53 for HR−/HER2−, and 0.61 and 0.43 for HR−/HER2+ BC. The gene discussed is ERBB2; the disease is neoplasm.