CD8A and neoplasm: This conclusion is supported by a series of provocative experiments using the pmel Tg/B16 model in which the adoptive transfer of naive or "early" IVS-effector pmel CD8+ T cells into lymphopenic tumor-bearing recipient mice resulted in much more durable tumor regression following hgp10025–33 vaccination and IL-2 therapy compared to the poor therapeutic effects observed using IVS expanded, highly stimulated intermediate or late-stage effector T cells [22].