CDH17 and cancer: Observations of heterophilic cadherin interactions have been reported during normal development of the endoderm,17 in establishing synaptic potentials within the hippocampus,18 and duringXenopus gastrulation,19 and are also noted in diseases such as cancer.20 In addition, the atypical cadherins Fat and Dachsous are capable of forming heterodimers between neighboring homotypic cells.21 Collectively, these results support the notion that heterophilic interactions can occur between different types of cadherins during development.