Brain diseases are diseases of enormous public health significance. Rfx4_v3 +/- mice are born with non-communicating congenital hydrocephalus, indicating that RFX4_v3 may contribute to the pathogenesis of hydrocephalus. In the Rfx4_v3 -/- brain, many genes that are crucial for brain morphogenesis are dysregulated, such as the signaling components in the Wnt, bone morphogenetic protein, and retinoic acid pathways, suggesting that RFX4_v3 may be involved in many aspects of brain development. Investigating the regulatory mechanisms that direct brain-specific and temporally correct expression of RFX4_v3 in vivo will help us to better understand the expression, regulation, and function of this critical transcription factor during brain development, and may further facilitate mechanistic studies into the pathogenesis of many brain disorders