The pcDNA3.1 plasmid, pcDNA3.1-PPARδ plasmid, pcDNA3.1-PPARδ + negative control siRNA (NC siRNA), and pcDNA3.1-PPARδ + NKD1 siRNA were consecutively transfected into colon cancer HCT116 and SW480 cells. The gene discussed is NKD1; the disease is malignant colon neoplasm.