| a1Feex · (TfR1) | iron import (via TfR1) with the rate a1 |
| a2 · (LIP) · (Fpn) | iron export (via Fpn) with the rate a2 |
| Feex | iron saturation level of extracellular transferrin |
| b and c | as described above. |
| a1Feex · (TfR1) | iron import (via TfR1) with the rate a1 |
| a2 · (LIP) · (Fpn) | iron export (via Fpn) with the rate a2 |
| Feex | iron saturation level of extracellular transferrin |
| b and c | as described above. |