The ZBTB family of proteins is comprised of diverse zinc finger proteins that also contain a BTB (BR-C, ttk and bab) domain. ZBTB9, also known as ZNF919, is present in multiple tissues, and is highly expressed in the cytoplasm of the placenta. While little is known about ZBTB9, other ZBTB proteins, such as ZBTB4 bind methylated DNA and repress transcription. Another ZBTB proteins, ZBTB7A, has been implicated as a proto-oncogene whose overexpression contributes to malignancy in breast cancer, suggesting that ZBTB9 may act as a transcriptional repressor or be involved in tumorigenesis.