STAT3 and gastric cancer: Depletion of STAT3 resulted in upregulation of E-cadherin expression in MKN1 and MKN7 cells but not in 58As9 cells (Figure 5B), consistent with the notion that STAT3 promotes cell migration and invasion through regulation of E-cadherin expression in gastric cancer cells in which STAT3 is activated by cell-derived IL-6.