Isolation of CD34⁺CD19⁺ pro-B cells from a patient with 5q− syndrome.

FACS profile shows CD19 (PE) versus myeloid (CD14/15-FITC) antigen expression on BM cells from patient no. 2, gated on CD34 (APC)-positive BM cells. Note the lack of coexpression of CD19 and myeloid antigens. In this patient, CD34⁺CD19⁺ cells represented 2% of the CD34⁺ cells, and 67% of these cells were 5q− according to FISH analysis.