Fig. 8From: Mathematical model of TGF-βsignalling: feedback coupling is consistent with signal switchingThe effects of SMAD concentration on the long-term response of PSMAD (500-2500 min). The PSMAD steady-state levels are calculated for two distinct ligand concentrations TGF-β = 2 and TGF-β = 5 (arbitrary units). The steady-state level of total PSMAD rises higher when TGF-β=5 than when TGF-β=2 due to the increase in the ligand concentration. Note that the units of PSMAD and SMAD concentration levels are arbitraryBack to article page