Consequences of Western blot and qRT-PCR assays revealed that EZH2 down-regulation significantly decreased EZH2 gene expression and increased RUNX3 gene expression in HCT116 and HT29 cells, indicating that EZH2 and RNX3 are negatively regulated at gene and protein levels in colon cancer, and EZH2 may interfere with colorectal cancer by up-regulating RUNX3 gene expression. This evidence concerns the gene RUNX3 and colorectal cancer.