 2. Patients with NSCLC confirmed by histopathology or cytology who need second-line chemotherapy, including progressive disease cases during or in 3 months posterior to end of first-line chemotherapy at least 4 cycles done and cases with intolerant adverse effects in first-line chemotherapy at least 4 cycles done; neo-adjuvant chemotherapy and targeted therapyEFGR-TKIs not to be served as first-line chemotherapy; 3 months of clearance needed for neo-adjuvant chemotherapy and 1 month for targeted and first-line chemotherapy; 