MAP kinase model. Panel (a) shows the MAP kinase model according to. It is assumed that the phosphorylated compounds are measured. The dynamics of all compounds is intended to be predicted to illustrate the prediction profile likelihood approach. In panel (b) the dynamics of the MAP kinase model as well as simulated data set are plotted. The 90% confidence intervals of the dynamic variables for predictions (dark gray) and for validation experiments (light gray) for this noise realization are plotted in panel (c). The size of the prediction confidence interval (PCI) is plotted as a dashed-dotted line. In absolute concentrations, the dynamics of Erk∗∗has the largest PCI at t = 181 seconds, i.e. when the negative feedback is activated. Also, the dynamics of Mek∗is only badly observable in our example. Measurements of both would be very informative for better calibrating the model.