Table 2.
PcG Expression in Normal Breast Tissues, Invasive Breast Carcinomas, and Precursors.
| Tissue | BMI-1 | RING1 | HPC1 | HPC2 | EZH2 |
| Healthy (n = 4) | 3 | 4 | 2 | 3 | 1 |
| DH, usual type (n = 4) | 4 | 4 | 1 | 4 | 1 |
| Atypical DH (n = 6) | 4 | 4 | 1 | 4 | 1 |
| DCIS, well differentiated (n = 5) | 4 | 4 | 2 | 4 | 1 |
| DCIS, poorly differentiated (n =5) | 4 | 4 | 1 | 4 | 2 |
| Invasive carcinoma, well differentiated (n = 4) | 4 | 3 | 1 | 4 | 1 |
| Invasive carcinoma, intermediately differentiated (n = 6) | 4 | 4 | 1 | 4 | 1 |
| Invasive carcinoma, poorly differentiated (n = 5) | 4 | 4 | 1 | 4 | 3 |
Nuclear PcG gene expression was investigated using immunohistochemistry and PcG-specific antibodies. Neoplastic cells were scored as follows: 1 = 0–25% positive cells; 2 = 26–50% positive cells; 3 = 51–75% positive cells; 4 = <75% positive cells.