HIF1A and breast cancer: Additionally, after treatment with radiation (10 Gy), sorafenib (5 and 10 μg/ml), radiation + sorafenib (10 Gy + 5 μg/ml and 10 Gy + 10 μg/ml) or DMSO for 72 h, immunoblotting of breast cancer cells under hypoxic and normoxic conditions showed different HIF-1α expression patterns (Fig. 3B and C).