By analyzing results of CD69low NSCLC patients (LC group, CD69low means the percentages of CD69+ cells in peripheral blood T cells are less than 5%), we found that the death rates of T cells (CD45+CD3+Annexin V+) and NK cells (CD45+CD3−CD19−Annexin V+) in the co-culture system containing PHA-activated PBMCs with or without PD-1 mAb were all significantly increased (Fig. 4C). This evidence concerns the gene PDCD1 and laryngotracheoesophageal cleft.