CD274 and non-small cell lung carcinoma: PD-L1 has been found to be expressed at high levels in most NSCLC patients and appears to be a favorable prognostic factor for early-stage disease, and higher PD-L1 expression is associated with a survival benefit in NSCLC patients (18, 19); however, there remains a subset of patients with PD-L1 TPS < 1% who could benefit from immunotherapy alone, suggesting that PD-L1 is an imperfect predictive biomarker (20, 21).