Abstract: Programmed deathligand 1 (PDL1), which is highly expressed in NSCLC, can be divided into two categories: membrane PDL1 and soluble PDL1. PDL1 participates in tumor immune escape through combining with its receptor. PDL1 immune checkpoint inhibitors have entered the phase Ⅰ studies and showed a good application prospect. It is also found that the sensitivity of PDL1 immune checkpoint inhibitors is strongly associated with the expression of PDL1 in tumor. Therefore, PDL1 can be used as a biomarker to predict its curative effect.

Key words: Carcinoma, nonsmall cell lung, Immunosuppressive agents, Programmed death ligand 1