PTGS2 and breast cancer: In fact, the pro-inflammatory nuclear factor kB (NF-kB) is involved in cancer development [6]; cytokines, such as cyclooxygenase-2 (COX-2), epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF), are the effectors of tumor tissue promotion [7]; HSPs, such as heat shock factor 1 (HFS-1) and hypoxia inducing factor (HIF-1), are widely studied in relation to BC [8].