ALK and cancer: In particular, crucial biomarkers for cancer detection and treatment efficacy in NSCLC have been identified in key genetic mutations: Epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), V-Raf murine sarcoma viral oncogene homolog B1 (BRAF), Kirsten rat sarcoma viral oncogene homolog (KRAS), and the c-ros oncogene 1 (ROS1) [12,13,14,15].