CD274 and neoplasm: A minimum of four to five endoscopic biopsies achieved a good concordance for both HER237,40,58 and PD-L1.62 This recommendation aligns with the ESMO guidelines, which suggest that obtaining five to eight endoscopic biopsies can provide a sufficient representation of the tumor.63 The average of tumor-containing biopsies in this study was 3, which is an important limitation.