CD8A and neoplasm: This increased cell killing effect of PBMC-loaded vMyx-mLIGHT, compared to virus alone or PBMCs alone, could be explained by the ability of virus-encoded LIGHT (which is expressed as a cell surface ligand from a constitutive early/late viral promoter in most primary leukocytes) to activate both CD8+ T cells and NK cells, both of which are powerful inducers of cytotoxicity against tumor cells [40].