HIF1A and neoplasm: In MPM cells, it has been demonstrated that increased 18F-FDG uptake is associated not only with an over-expression of GLUT-1 and hexokinase I, both reflecting an increased glucose metabolism needed for tumor growth, but also with an up-regulation of tumoral cells factors related to angiogenesis (such as vascular endothelial growth factor, VEGF), hypoxia (hypoxia-inducible factor-1 alpha—HIF-1a—cell proliferation (Ki-67 index), and cell cycle regulation (such as p53), which are well-known to be associated with a more aggressive behaviour and worse prognoses [39].