MIP1α, a chemokine facilitating the recruitment and activation of myeloid-derived cells, NK cell migration and the generation of a CD8+ cytotoxic T lymphocyte (CTL) memory responses21 were also secreted from infected DCs and macrophages and VVΔTKΔN1L infection markedly increased output from both these cell populations in vitro (figure 4E). This evidence concerns the gene CD8A and infection.