CD8A and neoplasm: Studies have shown that high levels of cluster of differentiation (CD) 8+ tumour-infiltrating lymphocytes (TILs) in HPV+ HNSCC tissues are associated with improved disease-free survival.4 Primed effector CD8+ cytotoxic T lymphocytes (CTLs) can exit the lymphoid tissue, move towards their target antigens, and identify such antigens in the context of major histocompatibility complex (MHC) class I molecules for target cell lysis.