PDCD1 and non-small cell lung carcinoma: PD-L1 expression and tumor mutation burden (TMB) have been used as clinical biomarkers to predict the response to PD-1/PD-L1 antibody therapy [5, 6], but, the prediction efficacy is sub-optimal when the PD-L1 expression is less than 50% in EGFR+/ALK+ NSCLC patients and non-squamous lung cancer patients [7].