In addition, tumor cells also express high levels of CD4+CD25+ Treg cells, which help direct immunosuppressive cytokines to the tumor microenvironment [28], so the decrease of the Treg cell may be helpful to remove the immunosuppressive effect for NSCLC patients, and our results also demonstrated a lower number of Treg cells. Here, CD4 is linked to non-small cell lung carcinoma.