Flow cytometric analysis of Fas-R expression on CD34⁺ cells derived from BM of CML patients. Total BM cells were stained with PE-conjugated CD34 and FITC-conjugated CD95 MoAb. Quadrants were set on the basis of cells treated with PE- and FITC-labeled isotypic controls. N.V., BM sample from a healthy volunteer; CML cp-1 to cp-5, BM samples from 5 patients with CML in chronic phase; CML bc, BM sample from a patient with CML in blastic crisis; AML, BM sample from a patient with acute myeloid leukemia. BM CD34⁺ cells were analyzed in the blast gate for CD95 expression.