CXCR4 and leukemia: It is known that the mobilization of immune cells in this compartment is mediated mainly by the CXCR4-CXCL12 pathway, and it has been shown that CXCR4+ γδ T cells (preferably Vδ1 cells) respond to CXCL2 in vitro, but their intramedullary homing abilities have not yet been evaluated in the in vivo context of leukemia (117–119).