Two chemokine receptor antagonists have now been approved by the FDA: the CCR5 antagonist maraviroc (Pfizer) for treatment of HIV/AIDS in patients with CCR5‐using strains; and the CXCR4 antagonist plerixafor (Sanofi) for hematopoietic stem cell mobilization with G‐CSF(CSF3, P09919) in patients undergoing transplantation in the context of chemotherapy for Hodgkins' Disease and multiple myeloma. Here, CSF3 is linked to plasma cell myeloma.