Regulating Cell Proliferation—As Easy as APC

A report in this week's issue of Science [Rubinfeld et al. ( p. 1023 )] places the tumor suppressor APC firmly in the signal transduction pathway triggered by WINGLESS (in the fruit fly Drosophila ) and WNT (in the mouse). This pathway is a supremely important one for control of cell fate. A second report [Matsumine et al. (p. 1020)] identifies a new downstream target of APC, another tumor suppressor Drosophila discs large ( dlg ). In his Perspective, Peifer discusses what these findings may mean for how APC participates in cell fate control.