Researches show that trastuzumab adjuvant chemotherapy significantly improves the disease-free survival rate of HER-2 positive breast cancer patients, and reduces the risk of recurrence and death.96–98 Although other anti-HER-2 drugs are currently available, such as pertuzumab and lapatinib, trastuzumab remains the gold standard for treating HER-2-positive breast cancer.99 If TAA with abnormal expression in the body can be identified before cancer occurs and mAbs can be used for intervention in a timely manner, it may prevent the formation or development of cancer cells. The gene discussed is ERBB2; the disease is cancer.