STAT3 and gastric cancer: The expression of IL‐6 and IL‐8 mRNAs was implicated in the early stage of tumorigenesis.35, 63 The media collected from GC lines have induced IL‐6 secretion in fibroblasts considered as the paracrine stimulant of proliferation of tumor gastric cells through the activation of STAT3 signaling.63 Besides, the upregulation of IL‐6 after the coincubation of fibroblasts with H. pylori (cagA+vacA+), we have observed a reciprocal increase in the expression of SDF‐1 mRNA.