Inclusion Criteria:  Histologically or cytologically confirmed NSCLC, with any tumor, node and metastasis (TNM) stage. Confirmed ALK gene rearrangement by any validated test. Confirmed the treatment with alectinib in the first line setting as systemic therapy in the medical record. Confirmed the start treatment with lorlatinib as the second/later-line therapy from 1st May 2019 to 31st December 2020.  Exclusion Criteria:  -Participating on any clinical trials of which final results has not yet been reported during the study period.