MTT assays and colony formation experiments revealed that the overexpression of PPARδ notably increased the colon cancer cell proliferation and that PPARδ overexpression with NKD1 gene expression knockdown remarkably hindered cell proliferation (Fig. 2B, C), indicating that PPARδ promotes colon cancer cell proliferation through NKD1. The gene discussed is NKD1; the disease is malignant colon neoplasm.