Figure 2.

Schematic illustration of the proposed cadherin-catenin pathway for contact inhibition, as well as possible disruptions of the pathway. Arrows and T-bars between the different genes, proteins, or cell states of the diagram indicate induction and repression, respectively. Minus and plus signs of different colors illustrate how various events can lead to a breakdown of this pathway: reduced expression of E-cadherins (red, upper signs), mutation of the APC tumor suppressor gene (orange, middle signs), and reduced expression or mutations of α-catenin (yellow, lower signs). Minus signs indicate either decreased concentrations or complete impairment of the associated proteins, and plus signs indicate increased concentrations compared with the healthy cell state.