CD274 and cancer: Previous biomarker research often relies on whole‐exome sequencing or RNA sequencing (RNA‐seq) of various cancer samples, which solely capture the overall genetic profile of cancers [5], such as programmed cell death‐ligand 1 (PD‐L1) expression [6], microsatellite instability (MSI) [7] and tumour mutation burden (TMB) [6].