HIF1A and neoplasm: Zhang et al. in their study found that hypoxia- and inflammation-related hypoxia-inducible factor 1α (HIF-1α) can stimulate the excessive expression of IL-1β in tumour-associated macrophages (TAMs), which, thanks to positive feedback, can induce the production of HIF-1α and facilitate the process of epithelial–mesenchymal transition (EMT), leading to metastasis [78].