Serum IGFBP-1 as a potential biomarker for diagnosis of early-stage upper gastrointestinal tumour oleh Yi-Wei Xu, Hao Chen, Chao-Qun Hong, Ling-Yu Chu, Shi-Han Yang, Li-Sheng Huang, Hong Guo, Liu-Yi Chen, Can-Tong Liu, Xin-Yi Huang, Lie-Hao Lin, Shu-Lin Chen, Zhi-Yong Wu, Yu-Hui Peng, Li-Yan Xu, En-Min Li