CD34⁺/CD86⁺ cells cultured in SCF plus GM-CSF acquire the surface phenotype of monocytes. Human marrow CD34⁺ cells were enriched by column immunoabsorption (A). CD34⁺/CD86⁺ and CD34⁺/CD86⁻ cells were purified by FACS-sorting through the gates shown in (A) and cultured for 9 days in SCF and GM-CSF. Sorted fresh (B) or cultured (C) cells were stained and analyzed by three-color microfluorimetry.