Table 2. Parameter mathematical notation, description, and units, where $i\in \left\{\mathrm{1,3}\right\}$ so that STAT $i$ corresponds to STAT1 or STAT3.

Parameter	Description	Unit
$r_{\mathrm{1,6}}^{+},r_{\mathrm{1,27}}^{+}$	Rate of receptor-ligand binding	nM−1s−1
$r_{\mathrm{1,6}}^{-},r_{\mathrm{1,27}}^{-}$	Rate of receptor-ligand dissociation	s−1
$r_{\mathrm{2,6}}^{+},r_{\mathrm{2,27}}^{+}$	Rate of monomer-monomer binding (or dimer formation)	nM−1s−1
$r_{\mathrm{2,6}}^{-},r_{\mathrm{2,27}}^{-}$	Rate of dimer dissociation	s−1
$k_{ia}^{+}$	Rate of STATi binding to GP130	nM−1s−1
$k_{ib}^{+}$	Rate of STATi binding to IL-27Rα	nM−1s−1
$k_{ia}^{-}$	Rate of STATi dissociating GP130	s−1
$k_{ib}^{-}$	Rate of STATi dissociating IL-27Rα	s−1
$q$	Rate of STATi phosphorylation on a dimer	s−1
$d_i$	Rate of pSTATi dephosphorylation	s−1
${\beta }_6,{\beta }_{27}$	Rate of receptor internalization/degradation under hypothesis 1	s−1
${\gamma }_6,{\gamma }_{27}$	Rate of receptor internalization/degradation under hypothesis 2	nM−1s−1
$\left[R_1\left(0\right)\right]$	Initial concentration of GP130	nM
$\left[R_2\left(0\right)\right]$	Initial concentration of IL-27Rα	nM
$\left[S_i\left(0\right)\right]$	Initial concentration of STATi	nM