Kinetic analysis of CD8+ T cells in different organs showed that CD8+ T cells from Kb-/-Db-/-M3-/- mice expanded almost 50 fold in the lung but only 3–4 fold in the spleen by day 60 post-infection (Fig 2A), suggesting that non-M3, MHC Ib-restricted CD8+ T cells expand more in the lung than in the spleen. Here, CD8A is linked to infection.