In recent years, although chemotherapy plus trastuzumab or nivolumab has been used as first-line treatment for advanced G/GEJ adenocarcinoma with HER-2-positive or high programmed death-ligand 1 (PD-L1) co-positive score, respectively (Bang et al., 2010; Jiang et al., 2022), the survival benefit remains low and the disease may rapidly recur or progress (Nakamura et al., 2021; Myer et al., 2022), necessitating the need to explore new molecular targets (Salati et al., 2023). Here, CD274 is linked to gastroesophageal junction adenocarcinoma.