In order to investigate whether the PCNP mediated STAT3/5 signaling pathway is involved in the pathogenesis of colon cancer, we transfected HCT166 and SW480 cells with sh-NC and sh-PCNP, followed by treatment with DMSO and 1 μm colivelin (STAT3 activator) for 24 h. The gene discussed is STAT3; the disease is malignant colon neoplasm.