This regulation of NK cells toward CD8 T cells has been previously described as a mechanism to prevent exacerbated CD8 T cell-dependent immune responses and to be critical in the control of immunopathology during mouse cytomegalovirus (MCMV) and lymphocytic choriomeningitis virus (LCMV) infections due to toxic levels of circulating cytokines produced by effector CD8 T cells (52, 53, 56). The gene discussed is CD8A; the disease is infection.