Several cancer-targeted drugs have been developed, including gefitinib for non-small cell lung cancer (NSCLC) with positive epidermal growth factor receptor (EGFR) expression, crizotinib for NSCLC with ALK mutations, sorafenib targeting VEGFR in various types of cancers, bevacizumab for metastatic colorectal cancer, and trastuzumab for breast cancer with HER-2 overexpression68. This evidence concerns the gene EGFR and metastatic colorectal cancer.