The presence and prevalence of the following lymphocyte subpopulations were determined in the peripheral blood of 113 patients with proven NSCLC at the first diagnosis by multiparameter flow cytometry: CD3−/CD19+ B cells, CD3+ T cells, CD3+/CD4+ helper T cells, CD3+/CD8+ cytotoxic T cells, CD3+/CD4+/CD25+/FoxP3+ regulatory CD4+ T (Treg) cells, CD3+/CD8+/CD25+/FoxP3+ regulatory CD8+ T (Treg) cells, CD3+/CD94+, CD3+/NKG2D+, CD3+/CD56+ NK-like T cells (NKT), CD56+/CD94+, CD3−/CD56+, CD3−/CD16+, CD3−/CD69+, CD3−/NKG2D+, CD3−/NKp30+, CD3−/NKp46+ NK cells. The gene discussed is CD4; the disease is non-small cell lung carcinoma.