CXCR4 and leukemia: In conclusion, our study suggests that leukemia derived EVs functionally compromise healthy HSPCs causing (i) an accumulation of less differentiated myeloid progenitors; (ii) a reduction of myeloid colony formation; (iii) an increased mRNA levels of inflammatory cytokines and growth factors and, finally; (iv) a reduction of CXCR4 expression and SDF1-mediated migration (Figures 8A, B).