HIF1A and pulmonary fibrosis: In the hypoxic lungs of patients with pulmonary fibrosis, hypoxia-inducible factor 1α (HIF-1α), the major transcription factor mediating cellular responses to hypoxia [5], is typically upregulated, and its downstream target genes (such as VEGFA and EPO) are also overexpressed [6] in order to restore oxygen delivery to the fibrotic lung.