PDA-66 leads to cell cycle arrest in G2 phase in RS4;11 and MOLT4 cells. ALL cell lines were incubated for 48 h with PDA-66 and cell cycle distribution was determined using Propidium iodide staining. On the left side the amount of cells in the different phases of cell cycle is shown for the two B-ALL cell lines SEM and RS4;11. On the right side the results for the T-ALL cell lines Jurkat and MOLT4 are displayed, respectively. G2 arrest could be detected in RS4;11 and MOLT4 cells. Treatment of Jurkat cells induced a decrease of cells in G0/G1 phase in favor of cells in S phase. Results are displayed as the mean + SD of three independent experiments. *Significant treatment effect vs. DMSO control, α = 0.05.