Your doctor may suggest to run tests on a tumor sample to identify the tumor-specific genes, proteins and other factors. Genetic mutations are known to contribute to the growth of lung cancer. These can often occur on one or more of several genes including EGFR, ALK, KRAS, BRAF, HER2, ROS1, RET, MET, TRK. Testing of these genes for earlier stages of the disease can also be performed. The results of these tests will help to decide if you should undergo targeted therapy or other treatment modalities.