PTGS2 and neoplasm: In turn, these phenotypic changes affected macrophage functions by enhancing their expression of tumor-promoting factors (ie, IL‐1β, IL-8 and VEGF), known to regulate malignant progression, through increased angiogenesis, leukocyte recruitment and tumor cell invasion.12 34 35 The relevance of this observation is sustained by previous works showing that the COX-2/PGE2 axis is a major player in cancer development and growth, acting through induction of angiogenesis and tumor invasiveness,36 promotion of M2 macrophage polarization37 and impaired recruitment and activation of immune cells.38