HIF1A and cancer: The resultant HIF-1 binds to its cognate transcriptional enhancer sequence, the hypoxia-responsive element (HRE), and induces the expression of various genes related to the adaptation of cellular metabolism to hypoxia (the switch from oxidative to anoxic respiration) [25], escaping from hypoxia (invasion and metastasis of cancer cells) [26, 27], and reduces hypoxia (angiogenesis) [28, 29], and so forth.