PTGS2 and cancer: Two important factors of inflammatory pathway in cancer are nuclear factor kappa B (NF-kB) and mitogen-activated protein kinase (MAPK), which are involved in the up-regulation of some pro-inflammatory mediators such as interleukin 1 (IL-1), IL-6, and TNF-α [69], and some inflammatory proteins such as C-reactive protein (CRP), cyclooxygenase-2 (COX-2), and lipoxygenase-2 (LOX-2), playing an important role, not only in inflammation, but also in angiogenesis, a fundamental process of tumorigenesis [70].