JAK2 and B-cell chronic lymphocytic leukemia: To study JAK2 role in chemokine signaling in B-CLL, and to evidence possible individual variability, we performed a comparative analysis of neoplastic B-lymphocytes isolated from a total of 41 B-CLL patients, by evaluating the activation state of JAK2 and its regulatory role in chemokine-induced LFA-1- and VLA-4-dependent adhesion.