Table 1 Immunostaining intensity classification
| Characterization | Symbolism | Staining intensity | Stained specimen |
|---|---|---|---|
| Negative | 0 | No staining reaction | < 20% |
| Weakly positive | 1 | Weak staining intensity | 20–50% |
| Moderate positive | 2 | Moderate staining intensity | 51–80% |
| Strongly positive | 3 | Strong staining intensity | > 80% |