Effects of Survivin transduction of the proportion of p21^+/+ and p21^–/– CFU-GM in S phase. FACS-sorted GFP⁺-transduced cells were treated with ³H-thymidine or cold thymidine before agar culture to enumerate the proportion of CFU-GM in S phase. Total CFU-GM in S-phase is shown as mean ± SEM for 3 experiments. – indicates vector control; W, Survivin; T34A, T34A Survivin.