IL7R and infection: More precisely, although the effector (memory) subset (CD62L−CD44high) showed a significant and sustained augmentation starting 7 days after a primary infection (Fig. 5b), this increase could not be attributed to the presence of actual memory cells among total spleen cells, as evidenced by the unchanged % in IL-7Rα+ cells within this subset (Fig. 5c and d, blue population and histograms).