HER2-targeted therapies, such as dual HER2 blockade (monoclonal antibodies such as trastuzumab and pertuzumab) or combinations of monoclonal antibodies with tyrosine kinase inhibitors (trastuzumab and lapatinib), have shown promise in a subset of metastatic colorectal cancer (CRC) cases, particularly in those resistant to standard therapies [78]. The gene discussed is ERBB2; the disease is metastatic colorectal cancer.