Importantly, inhibition of JAK/STAT3 signaling by the novel STAT3 inhibitor derepressed GATA6 expression in several gastric cancer cell lines suggesting that STAT3 is a transcription repressor for GATA6. It is noteworthy that GES cells with a low level of GATA6 promoter methylation did not express GATA6. On the contrary, SNU1 cells showing high levels of GATA6 methylation also showed a high level of GATA6 expression (Figure 2A,B). Here, STAT3 is linked to gastric cancer.