Archived paraffin-embedded and fresh frozen NSCLC tumor tissue will be obtained via the Department of Pathology. ALK positive status will be detected by Ventana immunohistochemistry (IHC) (Ventana Medical Systems, Inc. and Roche Diagnostics International, Inc). When ALK positive patients are detected, crizotinib will be administrated by various solutions based on physician's desecration and patients' willingness.