Abstract: KLF9 (Kruppellike factor 9) is the transcription factor that can bind GCrich sites through three C2H2type zinc fingers and can regulate diverse biological processes, including cell proliferation, apoptosis and the development of the organ. KLF9 is downregulated in some tumor specimens and tumorous cell lines relative to the normal samples and cell lines and plays an important role in the growth of cancer cells. Similar with the other KLF numbers, KLF9 could affect the development of tumors, especially for the endocrinerelated cancers through multiple signaling pathways and interventions with other proteins.

Key words: Neoplastic processes, Gene expression, Cell apoptosis, Kruppellike transcription factors