An increase in IFN-γ is often observed in CD8+ T cells after cancer immunotherapy, but the serum IFN-γ signature had no correlation with the OS of patients with squamous cell lung carcinoma.42 Moreover, elevated expression of serum IFN-γ was detected in the early post-treatment stage of immunotherapy, but no significant difference was noted at the late post-treatment stage (days 50–120), similar to our sampling time (post two cycles).43 44 Meanwhile, chemotherapy has been proven to attenuate the expression of proinflammatory cytokines.45 This evidence concerns the gene IFNG and squamous cell lung carcinoma.