The effective molecular characteristics of PD-1 inhibitor combination regimen as the first-line treatment for Chinese patients with HER2-positive gastric cancer: a real-world retrospective analysis study - Zhang, Lingyun; Guan, Bin; Li, Wei; Yu, Shan; Li, Qian; Yu, Yiyi; Cui, Yuehong; Sun, Debin; Wang, Yan (Translational Gastroenterology and Hepatology, 2025)