Moreover, the expression of COX-2 was significantly increased in invasive tumours compared with the non-invasive tumours (p=0.04).15 The same study evaluated prostaglandin E2, which has a positive role in cell proliferation, angiogenesis and inflammation, and a higher expression was observed in PTs, NFPAs and invasive PTs compared with normal pituitaries, FPAs and non-invasive PAs, respectively. The gene discussed is PTGS2; the disease is neoplasm.