CD8A and cancer: However, in cancer models, the decreased expression of NKG2D both on CD8+ T and on NK cellular surfaces was demonstrated, and it was determined to be a mechanism that compromises cell function and promotes tumor immune escape.26, 27 Regarding human CD56+CD8+ T cells, it has been demonstrated that this subpopulation is less vigorous in terms of proliferation, after which it is bound to classical class I HLA.