CD19 and B-cell chronic lymphocytic leukemia: The development of an array of phosphokinase inhibitors was a further, more recent, improvement grounded in a better knowledge of the transduction network downstream BCR, chemokine receptors, receptors for ligands expressed by a variety of microenvironment cells (including monocytes, T lymphocytes, stromal cells etc.), and other receptors on B-CLL cells (including CD19, CD5, CD38 etc.).