Gene expression profiling, for genes involved in regulating apoptosis, in HIF-1α silenced MDA-MB-231 cells incubated with or without paclitaxel under normoxic or hypoxic conditions. 8 h post transfection with HIF-1α siRNA (siRNA) or RISC-free control siRNA (RF) (50 nM, 24 h), cells were incubated under normoxic (N) or hypoxic (H) conditions with or without paclitaxel (tax, 50 μM) for 16 hours. After transfection and incubation, total RNA has been extracted and retro-transcribed in cDNA. TaqMan Human Apoptosis Array (Applied Biosystems) was used to perform real time PCR for 93 human genes implicated in apoptosis in addition to three endogenous controls. 18S was used as the house-keeping gene for data normalization. To validate results, single real-time RT-PCR reaction for BNIP3 and MCL1 were performed for independent samples. Results are expressed in induction level by comparison with the reference condition, normoxia. Please refer to supplementary data (Additional file 1) for results obtained for the 77 genes detected after real time PCR reactions.