Criteria to define the different TGF-β signaling responses. All responses must exceed a threshold concentration of 10 pM initially to be considered responsive. (A) Sustained responses: The response must reach 90% of the maximal value Opeak within 2 hours and retain 90% of this maximal value until the end of 10 hours simulation. (B) Transient responses: The response must exceed 10 pM and subsequently return to less than 10% of the highest value Opeak within 2 hours of stimulation. The final value Oend must be lower than 1 pM. (C-D) Oscillations: After the initial ≥10 pM peak at least four further peaks must exceed 1 pM in amplitude. Depending on whether the fifth amplitude is less or higher than half the second amplitude we distinguish (C) sustained and and (D) dampened oscillations respectively.
Cellière et al. BMC Systems Biology 2011 5:184 doi:10.1186/1752-0509-5-184