Correction: Site-specific immunoglobulin G N-glycosylation is associated with gastric cancer progression - Tingting Xu; Jianmin Huang; Jiajing Lin; Yuanyuan Liu; Yi Wang; Wenkang Shen; Jianjie He; Shuyun Chen; Xi Zhu; Yuqin Que; Mengting Hu; Yu Chen; et al. (BMC Cancer)