Krueppel-like factor 9 is a protein that in humans is encoded by the KLF9 gene. Previously known as Basic Transcription Element Binding Protein 1 (BTEB Protein 1), Klf9 is part of the Sp1 C2H2-type zinc finger family of transcription factors. Several previous studies showed Klf9-related regulation of animal development, including cell differentiation of B cells, keratinocytes, and neurons. Klf9 is also a key transcriptional regulator for uterine endometrial cell proliferation, adhesion, and differentiation, all factors that are essential during the process of pregnancy and are turned off during tumorigenesis.
