In the ≤ 6 months group, all the variables, age (HR 0.294, [95% CI, 0.114–0.760]; P = 0.011), left lung cancer (HR 0.271, [95% CI, 0.075–0.973]; P = 0.045), smoking (HR 3.519, [95% CI, 1.267–9.774]; P = 0.016), surgery (HR 0.077, [95% CI, 0.010–0.577]; P = 0.013), ECOG Performance Status (HR 16.329, [95% CI, 6.598–40.415]; P < 0.001), CRP 10–50 mg/L (HR 10.397, [95% CI, 1.288–83.951]; P = 0.028), IL-2R (HR 9.376, [95% CI, 1.122–78.323]; P = 0.028) were significant risk factors affecting OS in the univariate analysis. The gene discussed is CRP; the disease is lung cancer.