Overall, CD8 KO mice and most beta2-microglobulin-deficient mice controlled the challenge infection quite well; the few exceptions among the beta2-microglobulin-deficient mice could reflect the well-known fact that these mice not only lack CD8 T cells but also catabolize their Abs faster than normal mice and for that reason carry lower levels of Abs in addition to their T-cell defect (42). The gene discussed is CD8A; the disease is infection.