Notably, the co-incubation with AML exosomes reduced CXCR3 expression on NK-92 cells surface, suggesting that down-regulation of CXCR3 levels by AML exosomes might be ligand-mediated and responsible for the decreased migration of NK-92 cells into the tumor site [23] (Fig. 1b). Here, CXCR3 is linked to acute myeloid leukemia.