The frizzled (FRZ) module is a novel module type that was first identified in G-protein-
coupled receptors of thefrizzled and smoothened families and has since been shown to be
present in several secretedfrizzled-related proteins, in some modular proteases, in collagen
XVIII, and in various receptor tyrosine kinases of the Ror family. The FRZ modules constitute
the extracellular ligand-binding region of frizzled receptors and are known to mediate
signals of WNT family members through these receptors. With an eye toward defining the …