Cytoplasmic P4Hs that hydroxylate HIF-1α, a master transcriptional regulator of cellular responses to hypoxia and well-established mediator of cancer progression, have also been identified (prolyl hydroxylase domain enzymes; PHD1/EGLN2, PHD2/EGLN1, and PHD3/EGLN3). The gene discussed is EGLN3; the disease is cancer.