CD274 and non-small cell lung carcinoma: Nivolumab was superior to chemotherapy for NSCLC as a second‐line treatment, regardless of the degree of PD‐L1 expression,12, 13 but it was not significantly better than chemotherapy as a first‐line treatment.20 In other words, immunohistochemical staining of PD‐L1 expression using monoclonal antibodies is not a perfect predictor of treatment efficacy.