IFNG and lung cancer: The predictive values of plasma cytokines IL-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ alone for the mortality of lung cancer were 17.65%, 17.65%, 23.53%, 17.65%, 23.53%, and 17.65%, respectively, and the predictive value of the combination of the six cytokines for the mortality of lung cancer reached 47.06% (P < 0.05).