CD274 and neoplasm: The finding that the majority of strong PD-L1 protein positive cases (> 50% tumor proportion score) were not PD-L1 amplified and the existence of cases that were negative for PD-L1 protein within the PD-L1 amplified group indicates that there are other mechanisms to regulate PD-L1 protein expression, which are described for distinct genomic subgroups [5, 26, 27].