Low doses of Peg IFN-α 2a combined with Nutlin-3 significantly inhibited the proliferation of PV CD34⁺ cells. (A) After treatment with a low dose of Peg IFN-α 2a combined with Nutlin-3, the percentage of reduction in CD34⁺ cell numbers from PV and normal BM compared with cytokines alone. *P < .05. **P < .01. (B) Effects of 200 U/mL of Peg IFN-α 2a combined with 200nM of Nutlin-3 on CFU-GM- and BFU-E-derived colony formation by normal BM CD34⁺ cells. *P < .05. n = 7. (C) Effects of 200 U/mL of Peg IFN-α 2a combined with 200nM of Nutlin-3 on CFU-GM- and BFU-E-derived colony formation by PV CD34⁺ cells. *P < .05. **P < .01. n = 17.