CXCR4 and neoplasm: Accordingly, this interaction is suggested to be involved in treatment resistance and persistence of minimal residual disease.[22] By inhibiting the interaction of CXCR4 with its ligand CXCL12, several studies have reported that the tumor-promoting signals of stromal cells can be reversed, resulting in more chemotherapy-susceptible tumor cells and an increase in the spontaneous apoptosis rate [23–26].