In addition, clinical studies based on the chronic use of AMD3100 (i.e., market name of plerixafor) show beneficial effects on the mobilization of neutrophils and most subtypes of leukocytes [60], because patients suffer from panleukopenia, including lymphopenia, consistent with important roles for CXCL12/CXCR4 signalling in regulating haematopoiesis and immunity, as observed in patients and a mouse model of WHIM syndrome [149]. Here, CXCL12 is linked to WHIM syndrome.