PEBP1 and B-cell chronic lymphocytic leukemia: Moreover, in chronic lymphocytic leukemia (CLL), inhibition of RKIP by locostatin led to a decreased expression of the chemokine receptor CXCR4 and reduced the migratory capacity of CLL cells toward stroma-derived factor 1a (SDF-1a), being these effects of locostatin possibly mediated by the binding of GRK2 to MEK1 and AKT [76].