The NDRG (N-Myc downstream-regulated gene) family consisting of NDRG1, NDRG2, NDRG3, and NDRG4 are structurally related proteins with roles in cell proliferation, differentiation, apoptosis, stress responses, and cell migration/metastasis. NDRG1 was originally identified as a protein that was upregulated in N-Myc knockout mice. Proteins in the NDRG family, particularly NDRG1 and NDRG2, have been reported to be down-regulated in various cancer tissues and have been suggested to function as a tumor suppressors. Ubiquitously expressed N-Myc downstream-regulated gene 1 (NDRG1) is highly responsive to a variety of stress signals, including DNA damage, hypoxia, and elevated levels of nickel and calcium. Expression of NDRG1 is elevated in N-Myc defective mice and is negatively regulated by N- and c-Myc. Expression of NDRG1 and NDRG2 is upregulated by p53 and HIF-1 and contributes to apoptosis driven by those pathways. Research studies show that NDRG1 may play a role in cancer progression by p