Cascio et al. reported that miR-20b could regulate the expression of vascular endothelial growth factor (VEGF) in MCF-7 breast cancer cells under normoxic and hypoxia-mimicking conditions, which was mediated by hypoxia inducible factor 1 (HIF-1) and signal transducer and activator of transcription 3 (STAT3) [13]. This evidence concerns the gene STAT3 and breast cancer.