The results indicated that age ≤40, molecular subtypes of luminal B and HER-2 overexpression (infiltrating carcinoma), the larger the tumor, the higher the histological grade (infiltrating carcinoma), and the pathological type of infiltrating carcinoma were independent risk factors for sentinel lymph node metastasis of breast cancer (P < 0.05). The gene discussed is ERBB2; the disease is breast cancer.