Phosphorylation of these molecules and the activation of their downstream transcriptional targets, along with tyrosine phosphorylation of the dimerization domain at position 705 in the transcription factor STAT3, have been shown to be involved in proliferation, colony formation and tumorigenesis in a panel of MET-amplified gastric cancer cell lines, including KatoII [21]. This evidence concerns the gene STAT3 and gastric cancer.