P4HA1 and cancer: Chronic tumor hypoxia activates the transcription factor hypoxia inducible factor-1 (HIF-1), which controls the expression of many cancer-related genes, including those involved in glycolysis (e.g., LDHA, lactate dehydrogenase A; HK2, hexokinase 2), metastasis (e.g., P4HA1, prolyl 4-Hydroxylase Subunit Alpha 1; P4HA1, prolyl 4-Hydroxylase Subunit Alpha 1) and angiogenesis (e.g., ADM, adrenomedullin; ANGPTL4, angiopoietin-like 4) [9].