Breast cancer is the most common cancer among females worldwide, and it is ranked as the fifth leading cause of cancer death [1]. Anthracyclines and HER-2 inhibitor (Trastuzumab) are the mainstays of chemotherapy for breast cancer and although they prolonged survival in patients, they led to cardiac toxicity which ranges from mild asymptomatic decrease in EF to clinically overt form of heart failure. The gene discussed is ERBB2; the disease is breast carcinoma.