Significantly higher levels of serum IFN-γ were observed in younger (< 65 years old) NSCLC patients compared with older (> 65 years old), in contrast greater levels of serum TNF-α was found in older (> 65 years old) NSCLC patients compared with younger (< 65 years old) patients (P < 0.05) (data not shown). This evidence concerns the gene IFNG and non-small cell lung carcinoma.