Figure 1. Schematic representations of the regulatory pathway involving genes under the Notch (N) and FGF/Wnt (W) regulatory pathways.

The network nodes represent the enzyme levels, the blue arrows pointing into the nodes account for the processes of transcription and translation lumped together, and the blue arrow exiting from the nodes represent enzyme degradation.The regulatory processes are represented by red lines: the lines ending with arrowheads (bars) correspond to up-regulation (down-regulation). Finally, k accounts for the up-regulation of either gene W of the activity of its encoded protein by FGF and/or Wnt.