MethylCIBERSORT detected not only the increased TIL levels in HPV+ HNSCC compared with HPV− HNSCC (p = 2.167e−05, Wilcoxon’s Rank Sum Test) but more specifically attributed this to increased numbers of B (CD19+) and cytotoxic T (CD8+) lymphocytes (CTLs, Fig. 1f), in agreement with observations made using other methods, including immunohistochemistry and gene expression analysis24, potentially also helping to explain favourable prognosis displayed by this subgroup, independent of treatment modality25–27. This evidence concerns the gene CD8A and head and neck squamous cell carcinoma.