Non-metastatic cells 1 (NME1), also known as NM23-H1, originally identified as a candidate metastasis suppressor gene. NME1 is expressed in different tumor types where their levels have been alternatively associated with reduced or increased metastatic potential. Reductions in NME1 expression have been significantly associated with aggressive behavior in melanoma, breast, colon, and gastric carcinomas. On the contrary, high levels of NME1 gene expression are noted in the advanced stage of thyroid carcinomas.