||Notum is an evolutionarily conserved 60 kDa secreted deacylase that regulates Wnt activity. It is tethered to the cell surface by binding to Glypican-like sulfated proteoglycans, and it functions as a Glypican-dependent Wnt inhibitor. Notum hydrolyzes the palmitoyl moiety from Wnt-3a, making the Wnt more hydrophilic and unable to bind to the Frizzled-8 receptor. It also induces the release of cell surface GPI-anchored proteins such as Glypican-3, Cadherin-13, and uPAR. Notum regulates head regeneration in planaria, head formation and neural induction in Xenopus, and long range activity of hedgehog proteins in Drosophila. It is up-regulated in some human hepatocellular carcinomas and colorectal cancers. Within amino acids 88-458, mouse Notum shares 92% and 99% aa sequence identity with human and rat Notum, respectively.