The combination of gene hyperamplification and PD-L1 expression as a biomarker for the clinical benefit of tislelizumab in gastric/gastroesophageal junction adenocarcinoma.

"Declarations Conflict of interestS. Yang, X. Luo, Y. Shi, Y. Zhang, R. Huang, Y. Xu and Z. Shen are employees of BeiGene and hold BeiGene stock. Z. Lu, JS. Lee, S. Deva, T. Liu, Y. Chao, and L. Shen report no conflicts of interest. Ethical approvalAll procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1964 and later versions. Informed consent to be included in the study, or the equivalent, was obtained from all patients. Conflict of interest S. Yang, X. Luo, Y. Shi, Y. Zhang, R. Huang, Y. Xu and Z. Shen are employees of BeiGene and hold BeiGene stock. Z. Lu, JS. Lee, S. Deva, T. Liu, Y. Chao, and L. Shen report no conflicts of interest."

"Funding This study was sponsored by BeiGene, Ltd. Clinical Medicine Plus X -Young Scholars Project of Peking University (PKU2021LCXQ030), and the Pilot Project (3rd Round) to Reform Public Development of Beijing Municipal Medical Research Institute (2019-1)."