In ALK+ NSCLC, the ALK gene undergoes a rearrangement, called a translocation, within the chromosome to create a fusion between ALK and another gene 1).

1)
Solomon B, Wilner KD, Shaw AT. Current status of targeted therapy for anaplastic lymphoma kinase-rearranged non-Small-cell lung cancer. Clin Pharmacol Ther. 2014;95:15-23. PMID: 24091716