EML4 and non-small cell lung carcinoma: Multi-center samples will be selected for confirming these findings; 2 more clinical information should be analyzed, including EGFR and KRAS mutation status, EML4-ALK translocation, PD-L1 expression, which will contribute to emphasize the clinical relevance of circulating LINC00312 in NSCLC; 3 the diagnostic value of LINC00312 combination with existing serum biomarkers will be investigated.