CD16⁺ neutrophils and eosinophil-enriched CD16⁻ cell suspensions were prepared by MACS of the granulocyte fractions from CML patients and healthy controls. Total RNA was extracted and used as a template in an RT-PCR reaction using IL-4 or β-actin specific primers. The levels of specific amplification products were noted as −, +, ++, and +++, which correlate to absent, low, intermediate, and high expression, respectively. One representative experiment out of 3 is shown.