Effects of thalidomide on expression of γ- and β-globin mRNA in erythroid progenitor cells. CD34⁺ cells were cultured for 14 days in EPO and treated with different concentrations of thalidomide (0.01-100 μM) over the indicated time periods (days 0-14, days 0-6, or days 6-14). (A,C) γ-globin and (B,D) β-globin mRNA levels were quantitated by real-time PCR. Results are shown as means (± SD) from 3 different donors. *P < .05 versus untreated cells.