PDCD1 and lung cancer: With the identification and characterization of PD-1high and PD-1low T cell subpopulations in the tumour from multiple cancer types including lung cancer, hepatocellular carcinoma and nasopharyngeal carcinoma, we believe that it is important to evaluate if the PD-1 expression status on CD8+ TILs associates with the recurrence or the overall survival of cervical cancer patients (23–25).