HIF1A and neoplasm: HIF-1α expression is also regulated by mutations in tumor suppressor genes, such as VHL, p53, and PTEN [70,71,72] Moreover, overexpression of oncogenes that includes v-SRC, EGFR, HER2, and subsequent signaling through the phosphatidylinositol-3-kinase (PI3K) and mitogen-activated protein (MAP) kinase pathways activate HIF-1α expression [52,53,54].