Currently, the most commonly used predictive biomarker is PD-L1 expression as evaluated in tumor biopsies through immunohistochemical (IHC) staining; however, limitations are present, for example, PD-L1 expression is not always correctly assessed by core needle biopsy and this method cannot reflect the changes in PD-L1 expression over time 26, 27. The gene discussed is CD274; the disease is neoplasm.