Currently, despite having found a lot of biomarkers for ICI and OS such as different immune checkpoints, PD-L1 is the only one which has been widely confirmed, such as the validated effectiveness of pembrolizumab for nonsmall cell lung cancer selected with PD-L1 > 50% and the combination of atezolizumab and nab-paclitaxel for metastatic triple negative breast cancer with PD-L1 > 1% (Schmid et al., 2018; Reck et al., 2019). The gene discussed is CD274; the disease is lung cancer.