Fig. 7From: Mathematical model of TGF-βsignalling: feedback coupling is consistent with signal switchingThe effects of receptor concentration on the long-term response of PSMAD (500 min). The PSMAD steady-state levels are calculated for two distinct ligand concentrations TGF-β = 2 and TGF-β = 5 (arbitrary units). Approximately, no difference is observed between the two curves of this figure. Note that the units of PSMAD and receptor concentration levels are arbitraryBack to article page