To further confirm the link between JAK2 inhibition by AG490, SHP-1 activation and Lyn dephosphorylation/deactivation, we co-treated CLL cells with AG490 and sodium orthovanadate (Na3VO4, 100 μM), a known inhibitor of SHP-1 [26,27], in order to restore Lyn activation (resulting from the inactivation of SHP-1 phosphatase). The gene discussed is JAK2; the disease is B-cell chronic lymphocytic leukemia.