PDE4A and B-cell chronic lymphocytic leukemia: De Medeiros et al. [70] demonstrated that BC54, an inhibitor of PDE4 and PDE7 (IC50 = from 50–110 nM for PDE4A, PDE4B, PDE4D; IC50 = 140 nM for PDE7A and PDE7B) exhibited anti-inflammatory properties (reduction of TNF-α production by macrophages and decrease in IL-2 synthesis by PMA-PHA-stimulated Jurkat T cells) and elicited apoptosis in CLL cells.