A. Growth curve of MDA-MB-231 cells transduced with shSCR, shEPOR#1, or shEPOR#2 measured by MTT colorimetric assay to determine cell viability. shSCR vs shEPOR#1, ***p = 0.0003 at Day 3. shSCR vs shEPOR#2, ***p < 0.0001 at Day 3. B. Clonogenic assay of MDA-MB-231-shSCR, MDA-MB-231-shEPOR#1 and MDA-MB-231-shEPOR#2 cells. Colony number was quantified in three independent replicates after 5 days. shSCR vs shEPOR#1, **p = 0.002; shSCR vs shEPOR#2, **p = 0.0041. C. Immunoblots of PARP and Caspase 3 in MDA-MB-231-shSCR, MDA-MB-231-shEPOR#1 and MDA-MB-231-shEPOR#2 cells, and MDA-MB-435-shSCR, MDA-MB-435-shEPOR#1 and MDA-MB-435-shEPOR#2 cells harvested 72 hours after transduction. D. Immunoblots of apoptosis-related genes in MDA-MB-231-shSCR, MDA-MB-231-shEPOR#1 and MDA-MB-231-shEPOR#2 cells, harvested 72 hours after transduction. E. Immunoblots of cleaved forms of PARP and Caspase 3 in MDA-MB-231-shSCR, MDA-MB-231-shEPOR#1 and MDA-MB-231-shEPOR#1/siBim dual knockdown cells. Cell lysates were prepared 72 hours after knockdown. F. MTT activity of MDA-MB-231-shSCR, MDA-MB-231-shEPOR#1 and MDA-MB-231-shEPOR#1/siBim dual knockdown cells. Relative cell numbers were determined by MTT assay at both 24 and 48 hours. shEPOR#1 vs shEPOR#1/siBim at 24 hours, *p = 0.0121.