ALK and non-small cell lung carcinoma: Compared with NSCLC without rearrangement, the NSCLC stage of ALK gene rearrangement is later, and the brain is the most common organ of tumor metastasis and progression.[8,9] A retrospective study showed that the cumulative incidence of brain metastasis in 2 years and 3 years in patients with ALK-NSCLC was 45.5% and 58.4%, respectively.[10]