BTLA and B-cell chronic lymphocytic leukemia: Although at the protein level, we noticed in CLL patients the increased amounts (measured by MFI) of BTLA in circulating T cells (p = ns; Figure 2) and trend for a higher expression of CTLA-4 (both sCTLA-4 and cCTLA-4) molecules on/in BTLA+ T cells, (p = 0.056 and p = 0.056, respectively; Figure 5).