Frizzled-4 (FZD4) is also known as FzE4, CD344, which belongs to the G-protein coupled receptor Fz/Smo family. Most of frizzled receptors are coupled to the beta-catenin canonical signaling pathway, which leads to the activation of disheveled proteins, inhibition of GSK-3 kinase, nuclear accumulation of beta-catenin and activation of Wnt target genes. FZD4 contains one FZ (frizzled) domain. FZD4 may be involved in transduction and intercellular transmission of polarity information during tissue morphogenesis and/or in differentiated tissues. FZD4 interacts with MAGI3 and norrin (NDP).