One category of targeted drugs, is the targeting of specific genes with or without certain somatic mutations, such as osimertinib targeting at EGFR (with EGFR T790M mutation) and afatinib targeting at EGFR(with EGFRL858R mutations) in non-small cell lung cancer, vemurafenib targeting at BRCA(with BRAF V600 mutation) in melanoma, and panitumumab targeting at EGFR (with KRAS will type) in CRC. The gene discussed is EGFR; the disease is colorectal carcinoma.