CD4 and neoplasm: As these subsets are known to play a key role in immune surveillance and anti-tumor immune responses, which are dependent on the effective cooperation of monocyte-derived antigen-presenting cells (APC) in the stimulation of cytotoxic (Tc, CD3+CD8+) and helper T-cells (Th, CD3+CD4+), AbsCC and RelCC of these leukocytes are thought to be critical in the development of HNSCC.