Because CD8+ T-cells are well known for their tumor controlling capacities, and several studies linked the expression of perforin and/or GzmA and GzmB in DCs, human plasmacytoid DCs, and murine conventional DCs to the inhibition and even killing of T-cells in vitro [15,37,38], we first performed an in vitro co-culture between T-cells and WT or KO MDSCs to study the differences in T-cell suppression. This evidence concerns the gene PRF1 and neoplasm.