Differential expression of RXRα by monocytes versus neutrophil granulocytes. (A) Representative phenotypic analysis of human CD34⁺ cells generated in serum-free 72-hour expansion cultures (left panel; FL, SCF, TPO) or after subsequent culture for 10 days in granulocyte conditions (right panel; G-CSF, SCF). Center diagram shows cells from monocyte cultures (M-CSF, IL-6, FL, SCF) after FACS sorting for CD11b and CD14. (B) Western blot analysis (RXRα or β-actin control) of in vitro–generated cells shown in panel A (ie, CD34⁺ cells after 72-hour expansion; Mo's or Gs). Different lanes from 1 blot were grouped. Data are representative of 5 experiments. (C) Western blot analysis (RXRα vs actin control) of more than 95% pure peripheral blood CD14⁺ Mo's or CD15⁺LF⁺ Gs. (B-C) Protein extracts were prepared using SDS loading dye (“Materials and methods”).