Particularly, the PD-L1 expression on tumor cells is regarded as the best available biomarker to predict the efficacy of checkpoint inhibitors in NSCLC; although there is a linear relationship between the size of the benefit of immune check-point inhibitors and the level of PD-L1 expression in NSCLC, tumor responses have been observed also in patients with low or undetectable PD-L1 expression [291]. Here, CD274 is linked to neoplasm.