Dual-positive gastric cancer: an extremely malignant subtype of gastric cancer with high serum alpha-fetoprotein and carcinoembryonic antigen concentrations - Xie, Weixun; Hu, Chengyu; Liu, Hongming; Wu, Zelai; Luo, Bixian; Wu, Xiaoying; Tuo, Chuanlei; Deng, Ziyin; Liang, Han; Liu, Yong; Gong, Weihua (Frontiers in Oncology, 2025)