Erratum to: Intermittent high dose proton pump inhibitor enhances the antitumor effects of chemotherapy in metastatic breast cancer. Issue 1 (December 2015) - Wang, Bi-Yun; Zhang, Jian; Wang, Jia-Lei; Sun, Si; Wang, Zhong-Hua; Wang, Lei-Ping; Zhang, Qun-Ling; Lv, Fang-Fang; Cao, En-Ying; Shao, Zhi-Min; Fais, Stefano; Hu, Xi-Chun