ERBB2 and breast cancer: For example, one of the most successful FDA approved tyrosine kinase inhibitors (TKIs) indicated clinically for breast cancer treatment is lapatinib, which is used in combination with capecitabine for the treatment of patients with advanced or metastatic breast cancer (MBC) whose tumors overexpress HER2 and who did not respond well to treatment with an anthracycline [24].