Abstract: Mel-18 gene is one of the core members of the PcG (polycomb group,) family,which plays an important role in embryogenesis, cell growth and proliferation and self-renewal of stem cells. Mel-18 gene expressing abnormally has been related to human tumorigenesis, development process. Mel-18 serves as a tumor suppressor gene and inhibits tumor growth through transcriptional repression of Bmi-1 and c-myc. Mel-18 expression is decreased at transcriptional and translational levels in most human cancers including breast cancer, prostate cancer, and gastric cancer and other tumors. Mel-18 is expected to become a prognostic marker for human cancers.

Key words: Neoplasms, Genes, tumor suppressor, Mel-18