The frizzled gene, originally identified in Drosophila melanogaster, is involved in the development of tissue polarity. The mammalian homolog of frizzled as well as several secreted mammalian frizzled-related proteins (FRPs) have been described. The frizzled proteins contain seven transmembrane domains, a cysteine-rich domain in the extracellular region and a carboxy terminal Ser/Thr-xxx-Val motif. They function as receptors for Wnt and are generally coupled to G proteins. Upregulation of frizzled-10 mRNA in human cells may lead to carcinogenesis through Wnt- Beta-catenin-TCF signaling pathway activation. Frizzled-10 has been found to be upregulated in HeLa S3, NT2, TMK1 and MKN74 cancer cell lines as well as in colorectal and breast cancer.