Comparative analysis between CLL Ki67+ BTLA-positive and Ki67+ BTLA-negative T cell compartments showed no significant differences (Figure 3a), while in HC, we observed a higher proportion of Ki67+ BTLA-positive T cells over Ki67+ BTLA-negative T cells (p = 0.0001) (Table 2). Here, BTLA is linked to B-cell chronic lymphocytic leukemia.