Our results revealed that Cx43-expressing gastric cancer cells exhibited more efficient migration through the mesothelial cell monolayers than Cx43T154A and empty vector group cells, whereas the diapedesis efficiency of tumor cells in latter two groups was not significantly different, suggesting that the heterocellular GJIC between tumor and mesothelial cells is necessary to enhance diapedesis. This evidence concerns the gene GJA1 and gastric cancer.