(A) Viable cell analysis. MCF7 cells were treated with vehicles, 0.78, 1.56, 3.125, 6.25,12.5, 25, 50, and 100μM of either B13 or LCL521 for 48h and then MTT assays were performed. The results are expressed as a percentage relative to untreated cells and are presented as means ± st dev. of single experiment with 4 time replicates. (B) Effect of LCL521 on MCF7 cell cycle. MCF7 cells were treated with vehicle or with 1, 2.5, 5, 7.5 and 10 μM LCL521 for 24h. Cells were fixed with 70% ethanol overnight before adding 500μL RNase and PI solution. Samples were kept in the dark for another 45min before the FACS analysis. (n = 4, two times experiments with duplicates in each. * p<0.01). Representative flow cytometric analyses are shown in S3 Fig.