Next, we analyzed TL1A protein expression in the T-cell (CD3+), monocyte (CD68+), and B-cell (CD5+/CD19+ for CLL and CD19+ for healthy donors) subsets of CLL and healthy-donor PBMCs, using intracellular staining and flow cytometry in the presence of cytokine secretion inhibition (BFA). Here, CD5 is linked to B-cell chronic lymphocytic leukemia.