Tissue morphogenesis relies on cell–cell adhesion that is mediated by the cadherin superfamily of transmembrane proteins. Epithelial-to-mesenchymal transitions (EMTs) during gastrulation are typically accompanied by downregulation of epithelial (E-) cadherin and upregulation of a mesenchymal/neuronal (N-) cadherin. For instance, in the early Drosophila embryo, the E-cadherin gene shotgun is expressed in the future ectoderm, whereas the N-cadherin is expressed in the mesoderm. However, it is unclear if the switch in cadherin expression has a functional role, such as to segregate the mesoderm from the ectoderm. Furthermore, it is also not well understood whether the two cadherins engage different signalling and, hence, have different downstream effects. On page 1511, Maria Leptin and colleagues study the relevance of the pattern of E- and N-cadherin expression during Drosophila gastrulation. To that end, they disrupt the complementarity of E- and N-cadherin expression in the ectoderm and mesoderm, but, unexpectedly, do not find any effect on mesoderm morphogenesis, suggesting that the cadherin switch is not required to segregate germ layers. Instead, they show that the switch to N-cadherin allows efficient wingless (Wnt) signalling, which is required for appropriate mesoderm differentiation. This might be mediated by the differing abilities of E- and N-cadherin to bind to Armadillo, the Drosophila homologue of β-catenin, a known transducer of the Wnt signalling pathway. Taken together, the data presented here illustrate the important signalling roles cadherins have in development and tissue morphogenesis.