Low-Dose Metformin Reprograms the Tumor Immune Microenvironment in Human Esophageal Cancer: Results of a Phase II Clinical Trial - Wang, Shuhong; Lin, Yusheng; Xiong, Xiao; Wang, Lu; Guo, Yi; Chen, Yuping; Chen, Shaobin; Wang, Geng; Lin, Peng; Chen, Hongcai; Yeung, Sai-Ching Jim; Bremer, Edwin; et al. (Clinical cancer research, 2020)