The Transwell migration assay was performed as described (21 (link)). A total of 5×104 MGC-803 or GES-1 cells were plated on the top chambers of 8 µm pore size Transwell plates (Corning Incorporated, Corning, NY, USA). In order to perform the Matrigel-coated Transwell invasion assay as described (21 (link)), Matrigel and 8×104 MGC-803 or GES-1 cells were plated on the top chambers of 8 µm pore size Transwell plates (Corning Incorporated, Corning, NY, USA). The migration and invasion assays were conducted for 48 h; all experiments were performed at least three times in triplicate.