The reduced O2 partial pressure in tumour microenvironment, prompts tumour cell to activate specific pathways that, driven by the transcription factor Hypoxia-inducible factor 1-alpha (HIF1α), induce hypermetabolism to favour glycolysis, resistance to chemotherapy, neo-angiogenesis with an increase in local vasculature and finally, tumour metastasis. Here, HIF1A is linked to neoplasm.