Homogeneous expression of CXC chemokine receptor 4 (CXCR4) on G-CSF–mobilized peripheral blood CD34+ cells

We read with interest the article by Chelucci et al,[1][1] reporting chemokine receptor 4 (CXCR4) mRNA and protein expression on about 50% of steady-state circulating CD34+ cells. This expression pattern was coincident with that observed in resident normal CD34+ cells from bone marrow, where CXCR4