Stable states of the wild type network.

The values of nodes representing growth factors and transcription factors are tabled for every zone in the growth plate. As the Ihh/PTHrP feedback loop involves diffusion of ligands from the prehypertrophic zone into the resting zone and vice versa, the nodes in the network indicate the presence of diffused Ihh and PTHrP respectively. Furthermore, FGF18 diffuses from the perichondrium to bind FGFR3 in proliferating chondrocytes [9]. The presence of paracrine signalling is indicated in the table (ext or +ext if auto- and paracrine signalling are mixed).