Flow cytometric analysis of bone marrow of a CLL patient stained with CD34 FITC (HPCA-2), CD20 PerCP (L27), and CD5 PE (L17F12). Fifty thousand cells were aquired in listmode on a FACScan. The leukemic cells are depicted blue by simultaneous analysis of CD5 PE and CD20 PerCP, whereas the CD34⁺ cells appear as green. There is no population detectable coexpressing CD34, CD5, and CD20.