CD274 and neoplasm: Ilie and colleagues who used a scoring system from 0 to 3 depending on PD-L1 expression ( ≥ 50%, ≥ 5% and < 50%, ≥ 1% and < 5%, < 1%) reported a poor correlation between the PD-L1 expression assessed in biopsy specimens and the corresponding resected tumour in 160 patients with NSCLC (Ilie et al. 2016).