Fig. 3

A bistable autoregulatory motif presented in [30, Figure 3B]. a X is a gene, P is a protein that can form a dimer PP and then binding to X. The gene X will get expressed and produce P in both forms X and XPP. Finally there is a degradation of P. b The ODE system of the gene regulatory network in a. The variables \(x_1, x_2, x_3\) and \(x_4\) are standing for the concentration of the species X, P, PP and XPP respectively