GRK2 and leukemia: For example, miR-125b, a miRNA implicated in the pathogenesis of B-cell malignancies [15], targets GRK2 for downregulation in a variety of leukemia cells, and in this context, GRK2 downregulation has been proposed to play a key role in inducing resistance to the chemotherapeutic agent, daunorubicin (DNR) [16].