Due to the discovery of driver oncogenes, including mutation or rearrangement in epidermal growth factor receptor (EGFR), the Kirsten rat sarcoma (KRAS), anaplastic lymphoma kinase (ALK), ROS proto-oncogene 1 (ROS1), and rearranged during transfection (RET), and following the development of molecular-targeting agents, a new era of precision medicine has been started for NSCLC (2). The gene discussed is KRAS; the disease is non-small cell lung carcinoma.