| A: % of IHC + labeled cells | B: Intensity of IHC staining | Final score |
| 0 = 0% | 0 = no staining (blank control, background) | A × B = range from 0 to 9 |
| 1 = <30% | 1 = weak | |
| 2 = 30% - 60% | 2 = mild | |
| 3 = >60% | 3 = strong |