Fig. 3.

Interactions between the Notch and Wnt signalling pathways. Notch and Wnt signalling pathways interact in three main ways. a Co-operative regulation of transcriptional targets. When both pathways are active at the same time, additional targets that require input from both pathways can be transcribed. b Transcriptional targets of one pathway affect the other. In this case, one pathway activates expression of the ligand for the second pathway, resulting in sequential signalling. c Direct molecular crosstalk. Crosstalk can be inhibitory (left) or activating (right). If the pathways are linear, then crosstalk can alter relative output levels (quantitative—not shown). If more than one branch is activated downstream of a ligand (blue), then crosstalk can affect the type of response (qualitative—compare left and right with centre)