Upregulation of HIF-1α in hypoxic conditions promotes increases in pro-angiogenic factors, namely, vascular endothelial growth factor (VEGF), known to be overexpressed in many lung cancers, causing an increase in tumour endothelial cell and tumour cell proliferation and angiogenesis (Wieleba et al., 2022; Frezzetti et al., 2017; Becker et al., 2023; Zhao Y. et al., 2022). The gene discussed is HIF1A; the disease is neoplasm.