Metformin as an anti-cancer agent against bladder cancer acts via PD-L1 downregulation in an orthotopic mouse model. - Yeh, Chang-Ching; Tsai, Pei-Chu; Song, Yung-Deng; Low, Yong-Seng; Hsu, Chih-Hao; Yang, Shiu-Ju; Chen, Yih-Yuan; Dou, Horng-Yunn (BMC Cancer, 2025)