Data fitting of the selected solution for the observables. A: activated EpoR, [pEpoR]. B: activated cytosolic STAT5, [pSTAT5cyt]. Data from two replicates were used as independent experiments. The quantitative data obtained from the two experiments (data points represented as crosses for experiment 1 and points for experiment 2) are compared with the solution of the model identification process (lines). Experimental data were obtained from BaF3-EpoR cells (proB cells exogenously expressing the murine EpoR) stimulated with 5 units/ml Epo and normalised as defined in Sup. Mat. A1 [see Additional file 1].