In subgroup analyses, we found that BTLA rs1982809 polymorphism reduced the risk of NSCLC (nonsquamous cell carcinoma: GA vs. GG: adjusted OR = 0.79, 95%CI = 0.64‐0.97, and P = 0.026; AA/GA vs. GG: adjusted OR = 0.81, 95%CI = 0.66‐0.99, and P = 0.037; ≥59 years: GA vs. GG: P = 0.036; never alcohol consumption: GA vs. GG: P = 0.013; GA/AA vs. GG: P = 0.016; body mass index (BMI) ≥ 24 kg/m2: GA vs. GG: P = 0.030; GA/AA vs. GG: P = 0.041). The gene discussed is BTLA; the disease is non-small cell lung carcinoma.