KLF4, which is also known as the gut-enriched Kruppel-like factor (GKLF), is a zinc finger-containing transcription factor that belongs to the Kruppel-like family of transcription factors. KLF4 plays important roles during the proliferation and differentiation of epithelial cells. Especially, it is found predominantly in gut and has been shown to be expressed during growth arrest. KLF4 is also involved in cell cycle control since expression of KLF4 inhibits DNA synthesis by blocking the G1/S phase of the cell cycle.