Induction of CD25 (IL-2Rα) and CD122 (IL-2Rβγ) expression on cultured CD34⁺CD33^lothymocytes. CD34⁺CD33^lo thymocytes cultured for 1 or 3 days with IL-7, IL-1α, IL-6, SCF, and GM-CSF were analyzed for the correlated expression of CD34 and CD25 or CD34 and CD122. Background fluorescence was determined by sequential staining with isotype-matched irrelevant MoAbs, FITC-conjugated goat antimouse Igs, and PE-Cy5-conjugated isotype-matched irrelevant MoAbs.