ALK and lung adenocarcinoma: Overall, 25-30% of all lung adenocarcinomas have Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations, 15-20% have epidermal growth factor (EGFR) mutations, and 5% have anaplastic lymphoma kinase (ALK) mutations, while other mutations such as ROS1, MET1, and BRAF are present at a lower incidence [3].