A high-resolution magnetic tweezer was used in our results to explore binding mechanics between STAT3 and promoter region at single-molecule levels and we found that phosphorylation had an important influence on DNA binding of STAT3, furthermore, STAT3 didn't bind to promoter of miR-193a-3p without ATP which was consistent with our in vitro cell experiments that crosstalk between adipocytes and gastric cancer cells provided amounts of ATP for tumor cells. The gene discussed is STAT3; the disease is neoplasm.