ZFP161 is a 449 amino acid member of the Krüppel C2H2-type zinc-finger protein family. Localized to distinct regions within the nucleus, ZFP161 functions both as a transcriptional repressor of Thymidine Kinase (TK) and c-Myc promoters and as a transcriptional activator of the dopamine transporter (DAT) promoter. ZFP161 contains one BTB (POZ) domain and five C2H2-type zinc fingers which direct its specific localization and nucleic acid binding, respectively. Defects in the gene encoding ZFP161 may be associated with holoprosencephaly type 4 (HPE4), a structural anomaly of the brain characterized by a flattened nasal tip with no visible septum, hypotelorism, lack of nasal bridge, ptosis of the left upper eyelid and, in some cases, infant death.