We found that, number of total T cells, T helper cells, NK cells and NK CD8+ T cell subset populations were decreased significantly in lung cancer patients (before, during and after)induction of chemotherapy as compared to control subjects, while cytotoxic T cells and NK CD4+ T cell subsets were decreased significantly in lung cancer patients before and during induction of chemotherapy and noted to be increased significantly in lung cancer patients after induction of chemotherapy as compared to control subjects (Fig. 1). This evidence concerns the gene CD8A and lung cancer.