CD274 and neoplasm: Most studies in the development of diagnostic biomarkers focused on tumour microenvironment.8,9,31,32 Many mechanism-based biomarkers like PD-L1 expression and intratumoural lymphoid infiltration have been evaluated in tumour biopsy samples.31 Although certain predictability has been obtained, the significant variance in IHC antibody, staining conditions, and anatomical sites have dramatically compromised the reliability and practical applications.