CD4 and neoplasm: In HNSCC, HPV-positive TME demonstrated higher concentrations of CD4+ helper T-cells, cytotoxic CD8+ T-cells, CD103+ CD8+ tissue-resident memory (CD8+ TRM) T-cells and CD45RO+ memory T-cells compared to HPV-negative counterparts, supporting the hypothesis that antigenicity of HPV may augment anti-tumour immunity [16, 17].