CXCL12 and B-cell chronic lymphocytic leukemia: Another successful aptamer therapeutic is NOX-A12, a spiegelmer—an unnatural mirror image nucleic acid aptamer strand—which targets CXCL12/SDF-1, a key chemokine involved in the maintenance of the tumor microenvironment in chronic lymphocytic leukemia and multiple myeloma cancers (Hoellenriegel et al., 2014; Roccaro Aldo et al., 2014).