The Wnts

How do Wnts work? Developmental and cancer biologists have feverishly dissected the mechanism of Wnt signal transduction (see Figure; homologous vertebrate/invertebrate proteins are indicated in the legend). The prevailing dogma is that the Wnt signal causes β-catenin/Armadillo to accumulate in the nucleus where it acts together with the transcription factor TCF/LEF/Pangolin. But this might not be the whole story. In the developing chick limb bud, not all Wnts are sensitive to perturbations in β-catenin and TCF/LEF/Pangolin.