The Editors of JBUON issue an Expression of Concern to 'Amarogentin secoiridoid inhibits in vivo cancer cell growth in xenograft mice model and induces apoptosis in human gastric cancer cells (SNU-16) through G2/M cell cycle arrest and PI3K/Akt signalling pathway', by Jian-Guo Zhao, Ling Zhang, Xiao-Jun Xiang, Feng Yu, Wan-li Ye, Dong-Ping Wu, Jian-Fang Wang, Jian-Ping Xiong, JBUON 2016;21(3):609-617; PMID:27569081. Following the publication of the above article, readers drew to our attention that part of the data was possibly unreliable. We sent emails to the authors with a request to provide the raw data to prove the originality, but received no reply. Therefore, as we continue to work through the issues raised, we advise readers to interpret the information presented in the article with due caution. We thank the readers for bringing this matter to our attention. We apologize for any inconvenience it may cause.