CLDN9 and gastric cancer: ChiP-Atlas MACS2 analysis found that GATA6 and GATA4 regulate CLDN9 expression in the YCC3 and AGS gastric epithelial cancer cell lines, respectively, whereas KLF5, a transcription factor that binds to the GC boxes [89] and interacts with GATA4 and GATA6 [90] was the regulator in KATO III gastric cancer cells.