1. BTLA was expressed in tumor cells in 35 patients with NSCLC (40.2%).2. BTLA levels were significantly higher in NSCLC patients with lymphatic metastasis and high tumor pathological stage.3. Patients with positive BTLA expression had a shorter relapse-free survival (RFS) than those with negative BTLA expression. The gene discussed is BTLA; the disease is neoplasm.