In order to further investigate STC2 secretion changes in cell-cell interactions between normal epithelia and colon cancer cells, the intracellular expression and extracellular secretion of STC2 respectively was detected in a co-culture system of NCM460 and HT29 cells (NCM460:HT29) at 1:1 cell number ratio. The gene discussed is STC2; the disease is malignant colon neoplasm.