Previous studies suggested that the overall increase in the number of circulating T-cells, and particularly of Tαβ CD4−CD8+ cells, might result from an underlying immune response to tackle the re-activation of host pathogens (e.g., CMV and EBV), in line with the persistently maintained anti-CMV specific IgM and IgG serum levels in a background of a progressively more severe hypogammaglobulinemia, as confirmed here for CLL A/0 with both stable and increasing leukemia cell clones [23]. Here, CD40LG is linked to B-cell chronic lymphocytic leukemia.