Research has shown that a decrease in oxygen levels within the TME activates hypoxia-inducible factors (HIFs) [7], with hypoxia-inducible factor-1α (HIF-1α) participating in hypoxia-related responses within the TME, accelerating malignant tumor progression and playing an important role in tumor pathogenesis [8] (Figure 2). This evidence concerns the gene HIF1A and cancer.