P4HA2 and neoplasm: P4HA2 has been reported to co-localise with HIF-1α in peri-necrotic, i.e. hypoxic, areas within tumours.27,52 The hypoxia pathway has a complex role in tumour progression through enhancing angiogenesis, tumour proliferation, secretion of growth factors and other proteolytic enzymes.52 Therefore, P4HA2 overexpression might be a consequence of hypoxia related changes.