DNA damage specifically induces a G2/M-phase arrest in the absence of cytokine treatment.

32D cells expressing EPO-R(wt) or cells expressing both EPO-R(wt) and Bcl-X_L (32D–EPO-R/BclX_L) were cultured in medium lacking cytokine growth factors (−GF) or with 5 U/mL EPO. Subsequently, cultures were exposed to 4 Gy γ-IR (+γ) or were left untreated (−γ). Thirty-three hours after irradiation, cells were stained with PI and analyzed by FACS.