CD274 and non-small cell lung carcinoma: PD‐L1 expression via IHC remains the only clinically validated predictive biomarker for response to PD‐1/PD‐L1 immune checkpoint blockade in the non‐small cell lung carcinoma (NSCLC) setting and is increasingly utilised in a range of other solid tumours [3, 4, 5, 6, 7].