Effect of hypoxia and/or paclitaxel or epirubicin on Bim protein expression. MDA-MB-231 cells were incubated under normoxic (N) or hypoxic (H) conditions with or without paclitaxel (tax, 50 μM) or epirubicin (epi, 10 μM) for 16 hours. Bim was detected by immunofluorescence using specific Bim antibody (in green) and α-tubulin antibody was used to stain microtubules (in red). Nuclei were stained with Topro-3 (in blue). Observation was performed in semi-quantitative confocal microscopy.