Immunohistochemical analysis of tumor specimens
| PD-L1 | CD4/HPF | CD8/HPF | FOXP3/HPF | CD8/FOXP3 | CD8/CD4 | |
|---|---|---|---|---|---|---|
| Neck primary (pre-treatment) | 20% | 75 | 111 | 31 | 3.58 | 1.48 |
| Metastatic brain (post-treatment) | 10% | 53 | 69 | 9 | 7.67 | 1.3 |
HPF high-power field; immunohistochemistry methods described in Additional file 1