Some examples are trastuzumab for metastatic Her2+ breast cancer; erlotinib and gefitinib for epidermal growth factor receptor (EGFR) mutated metastatic lung cancer; cetuximab and panitumumab for RAS-wild type metastatic colorectal cancer, in addition to several treatments used in hematological malignancies, which are not the focus of this report. The gene discussed is EGFR; the disease is breast carcinoma.