CTLA4 and head and neck squamous cell carcinoma: For example, in HNSCC, more CD8 + and CD4 + FoxP3- T-cells were CD25-positive than in RCC, and in NSCLC, more CD4 + FoxP3 + and CD4 + FoxP3- T-cells were CTLA-4-positive than in RCC (Supplementary Data 6).