ZIC2 (also known as zinc finger protein of the cerebellum 2, HPE5, Zic family member 2 and odd-paired drosophila homolog) is a nuclear protein that functions as a transcriptional repressor and may regulate tissue specific expression of dopamine receptor D1. In mouse, knockout of Zic1 leads to aplasia of cerebellum and skeletal abnormalities. Mutation in Zic2 and Zic3 in mouse and/or human cause holoprosencephaly and heterotaxis, respectively. Holoprosencephaly is the most common structural anomaly of the human brain.