The EML4-ALK fusion gene is seen in a variety of tumors, such as mesenchymal large cell lymphoma, inflammatory myofibroblastoma, neuroblastoma and non-small cell lung cancer (NSCLC), which is caused by insertion of the short arm of chromosome 2. The discovery of EML4-ALK represents a molecular subtype of NSCLC with a unique clinical profile in this group of patients: failure to benefit from EGFR TKI-targeted therapy. The discovery of EML4-ALK is a step toward “individualization” of lung cancer treatment, as reported in a retrospective study by Kim et al. Some investigators have suggested that stepwise testing for genetic variants such as KRAS, EGFR, and EML4-ALK could be performed in NSCLC patients to differentiate the patient population more finely, thus maximizing the benefits for different subgroups of patients. The EML4-ALK gene is undergoing a similar research journey as the EGFR gene, but there is no doubt that the EML4-ALK fusion gene will become a new favorite for targeted therapy in the future.