CD274 and cancer: Tumours that express high levels of PD‐L1 may respond well to PD‐1/PD‐L1 directed immunotherapy and tumour PD‐L1 protein levels are used as a predictive biomarker for anti‐PD‐1–directed therapy in many human cancers (Patel & Kurzrock, 2015; Vaddepally et al., 2020; Zdrenka et al., 2024).