Even if some characteristics were similar among the different clusters, such as lymphopenia, and an elevated level of effector CD8+CCR7- T cells, some other characteristics were very different: low lymphocyte activation and senescence in cluster 1, extremely elevated level of plasmablasts in cluster 3, high CD4+ and CD8+ T-cell activation in clusters 3, 4 and 5, and high CD8+ T-cell senescence in clusters 2, 4 and 5. The gene discussed is CD8A; the disease is lymphopenia.