NDRG1 and malignant colon neoplasm: Since the first time NDRG1 was recognized as metastasis suppressor in colon cancer [40], accumulating evidences have demonstrated that NDRG1 was down-regulated in breast, prostate, pancreatic, and colorectal cancers [14–16, 18], showing anti-tumor and anti-metastatic functions of NDRG1.