Published online Mar 21, 2015. doi: 10.3748/wjg.v21.i11.3206
Peer-review started: July 24, 2014
First decision: August 15, 2014
Revised: November 13, 2014
Accepted: December 16, 2014
Article in press: December 16, 2014
Published online: March 21, 2015
Core tip: Tetraspanin CD9 is a cell-surface protein with four transmembrane domains and is found in several organs. Although CD9 was primarily identified as a tumor suppressor, it exhibits diverse functions through its association with various partner proteins. CD9 relates to tumor proliferation, apoptosis, migration, adhesion, and angiogenesis, therefore involving several steps of tumor formation: communication with the environment, dissemination, and metastasis. In this review, we describe the possibility of CD9 manipulation as a novel therapeutic strategy to improve clinical outcome in gastric cancer.