Our microarray data suggests that transcription of genes important for memory CD8 T cell function are differentially regulated in CD62Lhi memory CD8 T cells with time after infection, but it is unclear if differences in the transcriptional program with time after infection are due to 1) cell-intrinsic changes in gene regulation, or 2) a subset of memory CD8 T cells within the earlyM population selectively survives and comes to constitute the lateM pool. The gene discussed is CD8A; the disease is infection.