EGFR model parameter | | |

*S*_{R} | EGFR synthesis rate | NR^{b} |

*k*_{f} | EGF association rate constant (m min) | 9.7× 10 |

*k*_{r} | EGF dissociation rate constant (min) | 0.24 |

*k*_{er} | Unoccupied EGFR internalization rate constant (min) | 0.07 ± 0.02 |

*k*_{ec} | EGF internalization rate constant (min) | 0.10 − 0.25 |

*k*_{ec},+ 2C4 | EGF internalization rate,+ 2C4 (min) | 0.28 ± 0.02 |

*f*_{xr} | Unoccupied EGFR recycling fraction | 0.8^{c} |

*f*_{xc} | EGF recycling fraction | 0.5–0.7 |

*f*_{xc},+ 2C4 | EGF recycling fraction,+ 2C4 | 0.47 ± 0.06 |

*k*_{xc} | EGF endosomal exit rate constant (min) | 0.036 ± 0.003 |

*k*_{xc},+ 2C4 | EGF endosomal exit rate constant,+ 2C4 (min) | 0.034 ± 0.002 |

HER2 model parameter | | |

*S*_{H} | HER2 synthesis | NR |

*k*_{eh} | HER2 internalization rate constant, no EGF (min) | 0.012 ± 0.004 |

*k*_{eh} | HER2 internalization rate constant,+ EGF (min) | 0.027 − 0.059 |

*f*_{xh}^{−} | HER2 recycling fraction, no EGF | 0.94 ± 0.03 |

*f*_{xh}^{+} | HER2 recycling fraction,+ EGF | 0.94 ± 0.05 |

*k*_{xh} | HER2 endosomal exit rate constant (min) | 0.07 ± 0.01 |